      DFSee version 9.11 22-08-2008  (c) 1994-2008: Jan van Wijk
 =========================[ www.dfsee.com ]==========================

_______________________________________________________________________________

C O N T E N T S:
_______________________________________________________________________________

   Terminology used

Note: for command descriptions and usage examples see the other dfs*.txt files

_______________________________________________________________________________

T E R M I N O L O G Y   U S E D:
_______________________________________________________________________________

 dot-number     A numeric value, preceded with a period, which is used to
 .NNNNN         select a sector number from the sector list.
                The first sector in the list will be '.0' and the largest
                value depends on the DFSee version. (see "Sector list")
                Leading zeroes can be left out, so ".18" equals ".000018"
                It can have any number of digits, up to the maximum value.

                A .NNNNN number is a valid 'symbolic SN' as well ...
_______________________________________________________________________________

 Attempts       Attempts to read the contents of a sector from any store.
                When problems occur on reading, the read might be retried
                a number of times. The default for this is 0 (no retries),
                but it can be set to any number using the "-A:nnn" switch
                on startup The total number of retries that occurred on an
                open store will be displayed using the 'store' command.
_______________________________________________________________________________

 Auto-quit      A property that can be set explicitly using the -Q switch,
                or that is standard on selected commands like query.
                It results in DFSee quiting automatically after executing
                this command, if and only if the command was specified as
                a parameter to the program.

                This makes batch-procedures easier to read since no explicit
                '#q' command needs to be appended to the command line.
_______________________________________________________________________________

 Base           This is the base sector number (PSN) that equals LSN-0.
                When the current opened entity is a partition, it will be
                the PSN for the first sector of the partition being viewed.
                It is displayed at the end of the DFSee statusline and can
                also be displayed using the 'store' command.

                There is also a 'base' command that can be used to specify
                this base value manually, as well as the 'limit' value.
                It has options to set the BASE for various areas like
                freespace. The base and limit values will normally be set
                automatically when opening any entity like a partition.
_______________________________________________________________________________

 BootManager    A program that controls booting one out of several bootable
 BMGR           partitions on your harddisks. There are many implementations
 BM             residing either in their own partition, using some space in
                a FAT partition or only a few 'reserved' sectors near the
                master boot record (MBR).

                Well known boot managers are the IBM one (with OS/2 or eCS),
                the one used with Windows-NT/2000/XP (NTLDR + BOOT.INI), the
                Linux-loader LILO, and System Commander.
                Within DFSee most references to it deal with the IBM version
                of the BootManager which has been shipped with OS/2 since the
                earliest 2.0 releases. The latest incarnation as used on eCS,
                WSeB and the Convenience Packs MCPx/ACPx is fully integrated
                with the LVM technology used in those versions and also has
                better support for booting beyond the 1024 cylinder limit
                and 2nd/3rd disks.

                DFSee will display the IBM BootManager in its normal
                partition overview, and will indicate the exact version
                using the creator and label columns as follows:

                Format  Creator VolumeLabel     comment
                ======  ======= ===========     ============================
                BMGR    FDISK   MaxCyl:1023     Classic BM up to Warp-4 FP-14
                                                limited to 1023 cylinders or
                                                about 7.8 GiB on most disks

                BMGR    FDISK   I13X-aware      New BM, not LVM aware but can
                                                address beyond cylinder 1023

                BMGR    LVM     I13X-aware      Latest BM, uses LVM and can
                                                address beyond cylinder 1023

                In addition to this, there will be explicit warnings given if
                bootable partitions exist beyond cylinder 1023, and either the
                MBR-code or BMGR does NOT support the I13X convention.
_______________________________________________________________________________

 BOOT.INI       Windows (NT, 2000, XP) INI file for the windows boot manager.
 BOOTINI        This file is ASCII (readable) and contains several lines with
 BI             operating systems/partitions to be booted. If more than the
                original Windows installation is present, the user will be
                presented a boot menu at startup of the Windows partition
                with one line for evey available boot system.

                Since the partitions to be booted are identified using an index
                like '...partition(2), the file needs maintenance when the order
                or number of partitions changes.

                For this reason the correct BOOT.INI index for each partition is
                calculated by DFSee, and displayed in several places like the
                detailed partition view, and the 'part -s' table overview.

                For the FAT(32) and NTFS filesystems, DFSee has commands to find
                the file, and display the correct index-value for that specific
                partition. When incorrect, it can be updated as well using the
                BOOTINI command or related menu items.
_______________________________________________________________________________

 Boot sector    The very first sector of a filesystem that usually holds some
 Boot record    critical information about it like:
 BR             Boot code, used when the partition is bootable
 PBR            Geometry and size info (boot parameter block)
                Location of filesystem tables (FAT, MFT, Superblock, RootDir)
_______________________________________________________________________________

 CHS            Cylinder Head Sector (addressing)
                This is the classical way of addressing physical sectors
                on a disk. It is used in the PC's BIOS, in partition tables
                and in low-level disk I/O APIs (IOCTL, INT-13).
                In most implementations the addressing ranges are limited
                causing all sorts of problems with large disks/partitions.

                In partition tables, a second more important method of
                location specification is used, called 'LBA'

                Mismatches between the CHS and LBA values can cause warnings
                or errors from partitioning tools
_______________________________________________________________________________

 CHS dummy      CHS values used as placeholders when the 'real' values do
                not fit in the available space. (cylinder > 1023)
                There are several styles used in assigning these dummy values
                and some tools (OS/2 FDISK or LVM, PowerQuest Partition-Magic)
                give errors like 'partition table corrupt' when the 'wrong'
                style is used. DFSee accepts all the styles, and shows the
                the style used in the DISK and WALK displays (at end of line)
                The styles recognized and shown by DFSee are:

                Style:      0 = IBM           1 = PQ            2 = MS

                start-CHS:  1023 geo-1 geo    1023 real real    1023 255   63
                example     1023  254  63     1023  0    1      1023 255   63
                            1023  254  63     1023  1    1      1023 255   63

                end-CHS:    1023 geo-1 geo    1023 real real    1023 255   63
                example     1023  254  63     1023 254  63      1023 255   63

                used by:    FDISK/LVM/DFSee   PowerQuest tools  Microsoft


                Note that the 'real' value is the corresponding C, H or S
                value as calculated from the linear LBA value using the
                current geometry, and 'geo' is the number of heads or
                sectors for that geometry.

                Values that do NOT conform to any of these styles will result
                in a CHS warning for that partition, and the style will be
                shown as "BAD" in bright red with the DISK or WALK command.
_______________________________________________________________________________

 Clone          Make a sector by-sector copy of a disk, partition or volume
                to another. In DFSee this will be a store to store copy,
                where a store represents any disk, partition or volume.
                This allows large copy operations, like whole physical disks,
                without the need for intermediate image files.

                There are also COPY and MOVE menu items, and a MOVE command,
                that use the clone function but also update the partition
                tables automatically for the moved or copied partition.
_______________________________________________________________________________

 Cluster        A (small) group of adjacent sectors that are handled by the
                operating system as one allocation unit.
                It is used on FAT filesystems to allow large partitions at
                the cost of more wasted "slack" space, and on NTFS to balance
                performance, slack space etc.
                HPFS does not use sector clustering (or a cluster size of 1!)

                DFS will try to account for clustering where needed, for
                example in size calculations and where sector/cluster pointers
                are used in the filesystem internal structures.
_______________________________________________________________________________

 Compatibility  An LVM volume that can also be used/seen by older operating
 volume         systems, and that can be made bootable. The partition type for
                the partitions associated with this volume (always ONLY one!)
                has the usual values like 0x07 for HPFS and 0x06 for FAT16.

          Note: If you want to create a compatibility volume using LVM.EXE
                choose to create a volume that "can be made bootable"
_______________________________________________________________________________

 DFSCHECK       A DFSee procedure to collect information about filesystems
                present in partitions defined on disks.

                It is implemented as internal command 'dfscheck' as well as an
                external script for various operating systems (.CMD/.BAT etc).
                There is a menu-items as well that will run this procedure:

                  Actions -> DFSCHECK, Check filesystems -> ... select part ...

                The resulting files (DFSC*.p*) are REQUIRED by DFSee support
                for some recovery support requests by users of DFSee.
_______________________________________________________________________________

 DFSDISK        A DFSee procedure to collect information about disk partitions
                that are still present, or HAVE BEEN present at some time on
                a disk. The information can be used to recover the partitions.

                It is implemented as internal command 'dfsdisk' as well as an
                external script for various operating systems (.CMD/.BAT etc).
                There are also two menu-items that will run this procedure:

                  Actions -> DFSDISK,  Find partitions   -> ... select disk ...

                  Actions -> Find partitions, try harder -> ... select disk ...

                Where the first one is the default one to use, and the second
                one will search ALL sectors on a disk to find partitions and
                will be VERY SLOW for that reason.

                The resulting files (DFSDISKI.*) are REQUIRED by DFSee support
                for most recovery support requests by users of DFSee.
_______________________________________________________________________________

 DFSxxx         A generic term used as 'any of the available DFSee executables'
 DFSxxx.EXE     DFSDOS.EXE, DFSOS2.EXE, DFSWIN.EXE, dfsee
_______________________________________________________________________________

 Disk           A (physical) disk, usually containing one or more partitions.
                These are usually fixed disks in a computer system, driven by
                EIDE or SCSI controllers, but they can also be removable or
                external to the computer itself.
_______________________________________________________________________________
 Disk-list      DFSee specific list of media that are accessible as a 'disk'
                using the 'disk-id' inside DFSee. Media that can be 'mounted'
                to this list are physical disks, virtual disks, RAW images
                and Linux devices. By default, DFSee will mount all physical
                disks to this list at startup. The list can be displayed and
                maintained using the 'File -> Media management' menu.

                Note that mounting/unmounting from this list does NOT have
                any effect on the media or operating system, it just makes
                them available within DFSee ...
_______________________________________________________________________________

 DLAT           Drive Letter Assignment Table, the term used by IBM to refer
                to the basic LVM information about volumes, kept in the LVM
                information sector near the corresponding MBR or EBR sector.
                (in the last sector of the same track).
_______________________________________________________________________________

 DLAT-entry     A single entry in the DLAT, containing information about one
                partition. Just like the partition table, the DLAT contains
                exactly four entries, unused ones should be ALL ZEROES.
                If obsolete (non zero) entries are present, this can result
                in the "The partition table on this disk may be corrupt"
                message from the LVM program.
_______________________________________________________________________________

 EBR            Extended Boot Record
                It contains no boot code like an MBR but only a partition
                table that holds the location of a single logical partition.
                It usually is located on the cylinder just before the actual
                logical partition itself, at Head-0, Sector 1.
                Each EBR will also point to the next EBR if more logical
                partitions exist on the same disk.
_______________________________________________________________________________

 EBR-base       Location of the very first EBR sector, which is also the
                start of the complete 'Ext-container', and used as a base
                reference point for the location of all the following EBR
                sectors that are present
_______________________________________________________________________________

 eCS            eComStation, the client version of the latest OS/2 release
                as marketed by Serenity Systems. This is the OS/2 4.5x
                kernel delivered with a lot of additional Desktop enhancements
                and applications as well as an easier installation procedure.
_______________________________________________________________________________

 EFI            Extensible Firmware Interface
                EFI is a new standard for the interface provided by the
                firmware that boots PCs, based on the Extensible Firmware
                Interface Specification, Version 1.02 (Intel Corporation).
                It replaces many of the existing (BIOS, APM) standards.

                Microsoft supports EFI as the only firmware interface for
                booting 64-bit Windows operating systems.

                The new Apple MAC (iMAC, MacBook) computers introduced
                early 2006 and based on Intel chips will also use this.

                See GPT for the associated new partitioning style
_______________________________________________________________________________

 Ext-chain      Extended partition chain, this is the list of all extended
                boot records (EBR) each [except last] holding a partition
                table with two entries:

                         1) An entry for the logical partition involved,
                            with partition types like FAT (0x06), HPFS (0x07)
                            or any other defined type

                         2) An entry pointing to the next EBR in the chain,
                            with partition type 0x05 (standard) or 0x0f for
                            Windows-partitions beyond 1024 cylinders.

                The last EBR lacks item (2), by definition.

                There is an entry in the partition table in the MBR that points
                to the first EBR, this also has type 0x05 or 0x0f.
                (also see Ext-container)

                If an EBR lacks item (1), it is called an EMPTY container,
                which may cause problems with other partitioning tools!
                DFSee will never create an empty container, and you can remove
                them using the CLEANUP command. You cannot create any primary
                partition in a freespace area that contains such an empty
                container, and can not COPY/MOVE primary partitions there.
_______________________________________________________________________________

 Ext-container  The extended container is the area of the disk that includes
                all logical partitions (and NO primaries).
                It has an entry in the partition table in the MBR, and counts
                towards the limit of 4 entries total.
                This leads to the following two practical limits:
                - 4 primary partitions, and NO logicals, or
                - 3 primary partitions plus an unlimited number of logicals
_______________________________________________________________________________

 Extended-X     Extended container type 0x0f, as used by Microsoft Win9x.
                See also: Part-tables explanation
_______________________________________________________________________________

 Ext-Int-13     Extended INT-13, a new BIOS interface that breaks the 1024
                cylinder limit. Implemented on recent (EIDE/ATA) BIOS'es
 (DFSDOS)       and some operating system drivers (like Win9x Dosbox)
                Due to several problems with different implementations,
                DFSee will recognize the existence, but only use Ext-Int-13
                on disks really larger than the limit (1024 cylinders)

                Support for extended int13 by the IBM BootManager and the
                related MBR-code and OS/2 bootsectors is called "I13X"
_______________________________________________________________________________

 FAT            File Allocation Table, the most important structure in the
                classic DOS filesystem that also gave it its name.
                It is a table of cluster numbers that indicates the cluster
                that holds the next part of the current file or directory,
                or indicates that this was the last cluster.
                The first cluster of a file is pointed to by the directory
                entry that also has the filename, size and the flags.
                This way the location of each cluster of a file can be easily
                found by following this "allocation-chain".

                The size of one entry in this FAT is usually 2 bytes (16bit),
                and clusters of maximum 32KiB, resulting in the largest FAT16
                filesystem of 2GiB. (4GiB on Win-NT with 64KiB clusters)

                On small disks (and diskettes) a 12-bit FAT is used, and for
                really large disks the FAT32 filesystem was introduced.

                DFSee supports 12, 16 and 32-bit FAT filesystems.

                The FAT has no redundancy and is sensitive to errors like:
                - "lost clusters" where no directory entry points to the chain
                - "cross links"   where two allocation chains point to the same
                cluster at some point.
_______________________________________________________________________________

 FAT32          Version of the FAT filesystem that uses 4-byte = 32-bit FAT
                entries. This makes the maximum size of a FAT32 filesystem
                nearly unlimited. The FAT structure itself does take up a lot
                of space on the disk, and in memory when using the filesystem.

                FAT32 was introduced with Windows95, and is also supported on
                the other newer Windows versions (98, ME, 2000 and XP).

                OS/2 and eCS also support it through the 3rd-party installable
                filesystem FAT32.IFS made by Henk Kelder.
_______________________________________________________________________________

 fid            Freespace ID, the number that uniquely identifies a specific
                area of freespace on a disk, as indicated in the leftmost
                column in the standard DFSee partition table display.
_______________________________________________________________________________

 FNODE          File-Node in HPFS filesystem
                A descriptive sector that holds the most critical information
                about a file in the filesystem like Shortname, size information
                and allocation information. (date & time are in the directory)
                It is usually located just before the actual filedata, so just
                like files FNODES are scattered all over the HPFS volume.
                DFSee uses remaining FNODE information to find deleted files.

                Note that the filenode numbers that may be displayed are really
                just the SECTORNUMBER where the Fnode is located. It can be
                used directly to display the Fnode from a DFSee commandline.
_______________________________________________________________________________

 Freespace      An area on a partitionable disk that is NOT taken up by a
                defined primary or logical partition. Depending on the size
                and location of the freespace, it can be used to create new
                primary and/or logical partitions. DFSee classifies the
                available freespace areas to indicate what you can do:

                f0 = Wasted       : Freespace that can NOT be used at all,
                Freespace Wasted    because it is not in the ext-container and
                                    the partition table in the MBR is full.
                                    (max 4 primaries including ext-container)

                f1 = Primary      : Freespace where only a PRIMARY partition
                Freespace Primary   can be created because there is a primary
                                    partition between it and the ext-container.

                                    Also, the first track of the disk can never
                                    contain any logical partitions. If a disk
                                    has only logical partitions the first track
                                    (1 cylinder, typical 7.8MiB) will be empty.
                                    It CAN be used to put a primary partition
                                    of 1 cylinder (like IBM BootManager).


                f2 = Logical      : Freespace where only a LOGICAL partition
                Freespace Logical   can be created because the partition table
                                    in the MBR is FULL, or because the area is
                                    inside the ext-container.

                f6 = H-Logic      : Logical freespace that is just before the
                Freespace Logical   current ext-container. Creating a logical
                                    here will cause the ext-container to grow
                                    A primary partition can NOT be created here

                fa = T-Logic      : Logical freespace that is just after the
                Freespace Logical   current ext-container. Creating a logical
                                    here will cause the ext-container to grow.
                                    A primary partition can NOT be created here

                f3 = N-P/Log      : Freespace where you can create a logical or
                Freespace Pri/Log   a primary. The logical would be the first
                                    one, so the ext-container will be created
                                    at the same time too.

                f7 = H-P/Log      : Freespace that is just before the current
                Freespace Pri/Log   ext-container. Creating a logical here will
                                    cause the ext-container to grow. You can
                                    also create a primary partition here.

                fb = T-P/Log      : Freespace that is just after the current
                Freespace Pri/Log   ext-container. Creating a logical here will
                                    cause the ext-container to grow. You can
                                    also create a primary partition here.

                fc = EXT/Log      : Freespace containing an EMPTY ext-container
                Freespace EXT/Log   Creating a logical causes the ext-container
                                    to be updated correctly. However, before a
                                    primary can be created you should run the
                                    CLEANUP command to remove the empty container
                                    from the EBR chain!

                ff = Track-0      : This is a (small) area of space in the first
                Mbr + Track-0 Area  track of the disk where NO partition can be
                                    created, but that is sometimes used to
                                    install a boot manager or put special
                                    information (like LVM info).

                You will get these codes/descriptions with the 'pl f' command
                that lists all freespace areas in the greatest detail.
_______________________________________________________________________________

 FS             A filesystem is the structuring of data on a storage medium
 File System    that allows easy access to that data by creating directory
                information and ways to search, read and write data.
                A filesystem also may have provisions aiding in data recovery,
                security, compression and more ...
                There are dozens of implementations of filesystems with many
                different strategies to achieve the desired goals.
                In the PC (Intel) world the most used are FAT and FAT32, NTFS,
                HPFS, EXT2 and JFS. These are also the filesystems that are
                supported (more or less) by DFSee.
_______________________________________________________________________________

 FS-administration      Filesystem data structures describing its contents
                        The term may be seen used in DFSee CHECK output
                        with allocation errors (error value 000002):

                        - Allocation set but area is not in FS-administration

                The 'Allocation' is derived from information like the FAT or an
                explicit allocation bitmap, while the FS-administration is all
                the rest like the directory and file hierarchical tree.
_______________________________________________________________________________

 GB             Gigabytes, 10^9 = 1 000 000 000 bytes (decimal gigabyte)
 GiB            GibiBytes, 2^30 = 1 073 741 824 bytes (binary  gigabyte)
                For an explanation of the units see "IEC units"
_______________________________________________________________________________

 Geometry       The division of harddisk space in separate cylinders, heads
                and sectors per track, often referred to as CHS addressing.

                C ==> cylinder or number of cylinders
                      the position of R/W heads on the platters, each position
                      has access to a single track on each of the platters

                H ==> head     or number of heads, or tracks per cylinder
                      the active head-number for a single platter

                S ==> sector   or number of sectors per track
                      each track consists of a number of sectors (usually 63)

                The total number of available sectors is  C * H * S

                Now all of this is based on the physical layout of a tradditional
                harddisk, and does not very often reflect the physical reality.

                Modern harddisks have just a few platters, and a high number
                of cylinders and sectors per track. This can even vary on
                different areas of the disk. For the external interface it is
                translated to a 'normalized' CHS geometry called 'physical geo'
                or a simpler linear addressing scheme is used where the sectors
                are simply numbered starting with 0 called logical block
                addressing or LBA.

                PC systems however carry the legacy of BIOS interfaces that use
                CHS type addressing on those interfaces. For capacity reasons
                that is often NOT the physical geometry as used by the disk
                itself, but a more convenient logical-geometry.

                Within DFSee three different geometries are used, see the
                corresponding descriptions for:  P-Geo, L-Geo and S-Geo
_______________________________________________________________________________

GPT             GUID partition table
                The new partitioning style used in EFI compatible systems.
                This has been an optional style ever since windows 2000,
                besides the classical MBR/EBR style of partition tables
                called 'basic' disks in those Windows versions.

                The new Intel based Apple iMAC and MacBook systems are
                said to use this partitioning scheme (and EFI) as well.

                A partition is a contiguous space of storage on a physical
                or logical disk that functions as though it were a physically
                separate disk. Partitions are visible to the system firmware
                and the installed operating system. Access to a partition is
                controlled by the system firmware and the operating system
                that is currently active.

                For 64-bit Windows, bootable hard drives must be partitioned
                using the GPT mechanism defined in EFI 1.0. GPT is also the
                default partitioning scheme used by 64-bit Windows for all
                non-removable storage media. GPT complements the older MBR
                partitioning scheme that has been common to PCs.

                - Well defined and fully self-identifying. Data that is
                  critical to platform operation is located in partitions
                  and not in unpartitioned or "hidden" sectors.
                - Uses primary and backup partition tables and CRC fields
                - Each partition has a unique GUID and a partition content type
                - Each GPT partition also has a 36-character Unicode name

                To protect GPT-partitioned disks from tools that only understand
                MBR such as Windows Disk Administrator or Fdisk, which do not
                know how to properly access a GPT diskeach GPT disk has a
                Protective MBR, beginning in sector 0. This sector precedes
                the GPT partition table and contains one type 0xEE partition
                that spans the disk.

                DFSee will correctly identify such 0xEE partitions but
                does NOT support further analysis or display of the real
                partition information inside a GPT partitioned disk.

                See also: EFI
_______________________________________________________________________________

 HiddenSectors  A field in most partition bootsectors (PBR) that most often
 and/or         contains the number of sectors between the PBR and the sector
 LBA-offset     that contain the partition table entry for it (MBR or EBR)

                This value is related to the "LBA offset" value that is in
                the partition tables, and in the DFSee display it is actually
                called the "LBA offset value".

                When incorrect, the partition might be ignored or fail to mount
                properly by an operating system. This is know to be the case
                for FAT filesystem under OS/2 and some others.

                DFSee has a specific fix command 'fixhs' to correct this value
                which is also available in most FS specific menus as:

                                "Fix HiddenSectors/GEO value"
_______________________________________________________________________________

 HPFS           High Performance FileSystem
                Offered as a real improvement over the classic FAT filesystems
                with the OS/2 1.2 Operating System. Its main advantages were
                faster access, more reliable error recovery and better handling
                of large disks. There is also a (server) version called HPFS386
                that adds native security information to the filesystem.
_______________________________________________________________________________

 I13X           Extended Int-13 support as used by the IBM BootManager and MBR
_______________________________________________________________________________

 IEC units      This describes a fairly new standard (IEC 60027-2, 1999) that
                attempts to create an unambiguous naming system for quantities
                used in (computer) systems that use the binary number system.

                In the International Standard Units (SI) the prefixes K, M
                and G are defined as powers of 10. Because the binary value
                2^10 = 1024 is roughly the same as 10^3 = 1000, these same
                prefixes were hijacked by the computer community for their
                binary multiples as well.

                Now that more people are starting to use computers, this causes
                more and more confusion. In the disk-storage field this is most
                visible with the capacity of harddisks. Disk manufacturers love
                to use the decimal kind of Megabyte, because that gives them
                the largest number to show for capacity ...

                However, most software tends to use the 'binary' form of these
                units and calculates a slightly lower number.

                Example: If you buy a "30 GB" harddisk, and format that as one
                big partition, your software will probably tell you that you
                got a 27.9 GB partition. So where did those 2 GB go ?

                Answer: Nowhere, 30GB is 30 000 000 000 bytes which is the
                equivalent of  27.9 times 1 073 741 824 (2^30).

                Now this will get easier once all software starts using the new
                prefixes. In the above example the "GiB" prefix should be used.

                An overview of the proposed prefixes and their values:

                                                  Analogous     Short prefix
                Factor Name Symbol Value          SI prefix     Relationship
                ====== ==== ====== ============== ============  ===============
                2^10   kibi Ki              1 024 kilo (10^3)   KiB = 1024 byte
                2^20   mebi Mi          1 048 576 mega (10^6)   MiB = 1024 KiB
                2^30   gibi Gi      1 073 741 824 giga (10^9)   GiB = 1024 MiB
                2^40   tebi Ti  1 099 511 627 776 tera (10^12)  TiB = 1024 GiB

                b = bit       B = BYTE

                DFSee, starting with version 5.21 will uses the new prefixes in
                all possible places and add a full-decimal value in bytes in
                some selected places. KB, MB and GB values will be avoided.

                For more info see:

                        http://www.pcguide.com/intro/fun/bindec.htm
                or
                        http://physics.nist.gov/cuu/Units/binary.html
_______________________________________________________________________________

 INODE          Information-Node in JFS (and other unix-like) filesystems
                A descriptive sector that holds the most critical information
                about a file in the filesystem like size information, data and
                time, extended-attributes and allocation information.
                It is located in allocated 'inode-extents' in groups of 32
                that are physically near the files they refer to.
                DFSee uses remaining INODE information to find deleted files.
_______________________________________________________________________________

 INT-13         DOS Interrupt-13, the classical way to interface to
                physical disks in DOS. Limited by design to 1024 cylinders.
 (DFSDOS)       Maximum disksize, when using BIOS disk-translation like LBA
                is just below 8GiB (1024 cylinders, 255 heads, 63 sectors)
_______________________________________________________________________________

 JFS            Journalling File System
                A filesystem originally developed by IBM for the AIX operating
                system sharing a lot of features with other UNIX filesystems
                and adding journalling on all filesystem metadata operations.
                This greatly reduces the time to check and repair any damage
                after crashes or other disasters (CHKDSK).
                First offered for OS/2 with WSeB and now also available in eCS
                and the Convenience Packs 1 & 2 for the Desktop.
                The OS/2 implementation requires LVM, and is not bootable (yet)
_______________________________________________________________________________

 KB             Kilobytes, 10^3 = 1 000 bytes (decimal kilobyte)
 KiB            KibiBytes, 2^10 = 1 024 bytes (binary  kilobyte)
                For an explanation of the units see "IEC units"
_______________________________________________________________________________

 Large-disk     Use of extended container type 0x0f, as used by Microsoft Win9x
 support        See also: Part-tables explanation
_______________________________________________________________________________

 LBA            Linear Block Addressing
                The most simple way to describe a position by using the
                number of sectors from some reference point to a sector.
                The default reference point is 0 (start of disk, MBR)
                but the EBR-base or location of current EBR are used too

                LBA style partition table fields define this offset plus
                the total size in sectors, as opposed to the absolute
                positions specified by their CHS counterparts.
_______________________________________________________________________________

 LBA offset     A field in the partition table entry that specifies the
                position of the defined partition as an offset.
                The 'base' for this offset is either 0 (MBR position) or the
                position of the first EBR in the chain (the 'EBR-base') or
                the position of the current EBR sector (the 'thisEBR' value)

                For a primary partition:
                The offset from the partition table-sector (MBR so always 0)
                to the location of the partition bootsector.

                For the first extended-container (type 05 or 0f) in the MBR:
                The offset from MBR = 0 to the first EBR in the chain.
                This position is reused in other logical offsets, and DFSee
                calls it the "EBR-base".

                For a logical partition:
                The offset from this EBR to the partition bootsector.
                Normally this is equal to the nr of sectors/track (0x3f = 63)

                For all other extended-containers (type 05 or 0f in an EBR):
                The offset from the EBR-base to this target EBR.

                Note: The HiddenSectors field in most bootsectors (PBR) is
                      related to this value, and in almost al cases should
                      have exactly the same value.
_______________________________________________________________________________

 LCN            Logical Cluster Number, used in filesystems that store cluster
                numbers internally (and in their bootsectors) like NTFS does.
_______________________________________________________________________________

 LFN            The long version of the file/directory name that is kept in a
 (VFAT)         VFAT directory. This name is using UNICODE (not ASCII).
                It is used on Win9x and Win-2000/XP FAT filesystems (16/32 bit)
_______________________________________________________________________________

 Limit          This is the largest LSN (Logical Sector Number) that can be
                used with the currently opened store. For a partition, that
                will be the last sector in the partition. The limit value can
                be displayed using the 'store' command. The 'base' command can
                be used to specify a 'limit' value manually when desired.
                The base and limit values will normally be set automatically
                when opening any entity like a partition.
_______________________________________________________________________________

 L-Geo          Logical geometry
                This is the most important geometry within DFSee since ALL the
                translations between Logical Block Address (LBA), or Physical
                Sector Numbers (PSN) as they are called within DFSee, and any
                CHS (Cylinder Head, Sector) values are done using this L-Geo.
                The initial values are retrieved from the Operating System,
                but this CAN be changed using the GEO command. The GEO command,
                without any parameters lists the L-Geo for the current disk.
_______________________________________________________________________________

 Logical        A partition listed in a partition table in an extended boot
 partition      record (EBR) inside the extended-container.
                By convention, the EBR is located at the start of a cylinder,
                at Head-0, sector 1 and the actual partition (bootsector)
                starts at Head-1, sector 1.
_______________________________________________________________________________

 LSN            Logical Sector Number
                This is the zero-based, unsigned 32-bit, number for a
                sector on a logical partition. The partition can be seen
                as a linear sequence of sectors.
                Note: when accessing a whole disk, the LSN equals the PSN
_______________________________________________________________________________

 LsnInfo        A value combining an LSN and a (small) informational value in
                a single 32-bit number. It can be kept in the sector list and
                the sector lookup table, and most operations will recognize
                and handle it correctly.
                One example of usage is the directory sector LSN plus the
                index of a directory entry for (V)FAT directories.
                LsnInfo 78000345 combines LSN 00000345 with index 7 and a
                single bit to mark it as an LsnInfo value (flag 0x08000000)
                So this points to the 8th directory entry in the directory
                sector at LSN 0345. (entry-numbers start counting at 0 :-)
_______________________________________________________________________________

 LVM            Logical Volume Manager, an 'FDISK-like' program plus related
                Operating System drivers on OS/2 Warp Server for e-Business,
                the Convenience Pack (client) and the new eComStation client.
                LVM allows more flexible naming and usage of partitions and
                drive-letters, including joining multiple partitions on more
                than one disk into a single volume.
                DFSee respects the drive-letters as assigned with LVM and has
                special display options like the 'PLIST LVM' command in FDISK
                mode. Also the 'part' display will show volume and partition
                names as well. (TIP: use a display-size wider than 80 columns)
                The SETBOOT command is also compatible with the newer LVM-type
                IBM BootManager. This allows setboot to be used from NT/DOS too.

                Note: Creating new partitions will NOT (yet) also create the
                      required LVM info, unless the -L option is specified.
_______________________________________________________________________________

 LVM info       The basic LVM information like partition name, volume name,
                drive-letter, bootable flag and some more stuff, that is kept
 (IBM: DLAT)    in the LVM-information sector, near the MBR or EBR for the
                partition in question. For primaries, it will contain info
                on ALL primaries in a single sector, each partition using one
                DLAT-entry. LVM info is transparant to other operating systems

                If you think of the partition-tables as the Table-Of-Contents
                for a disk, think of the LVM-info as a footnote with that TOC.
_______________________________________________________________________________

 LVM signature  Extended LVM information like disk-spanning and bad sector
                administration that is kept for LVM partitions (type 0x35)
 (IBM: BBR)     only. It is located at the very last sector of a partition
                and the related information usually takes up the entire
                last cylinder of the partition.
_______________________________________________________________________________

 LVM volume     A confusing term used by LVM for extended compatibility volumes.
                It has a fixed type value of 0x35, and can have more than one
                partition associated with it. It is most often used for JFS
                filesystems, but HPFS or FAT is also possible.
                An LVM-volume allows disk-spanning and multiple partitions,
                but it is currently NOT possible to boot from it.

                Note: Working (non-IBM) bootable JFS appeared in 2004

                With a JFS filesystem in an LVM-volume you can expand the
                volume to make it bigger (by adding partitions).

                An HPFS or FAT filesystem in an LVM-volume will only be seen
                by an LVM-aware operating system, so it is HIDDEN for other
                operating systems. (can be used to manipulate drive-letters)
_______________________________________________________________________________

 Magic          A term used with the DFSee specific filename/path recovery
 recovery       when recovering (or undeleting) files on a JFS filesystem.
 filename       This is also used to display this info in various places.

                Since JFS, as most Unix-like filesystems does NOT have any
                filename information with its files (Inodes), and the actual
                name in the directories is lost when deleting a file, some
                mechanism is needed to provide a meaningfull name on recovery.

                In DFSee there are FOUR methods to get such a name:

                1) Use a file/dir name cache built by scanning the tree (SLT)
                2) Use previously saved name info from the Inode     (SLT -M)
                3) Use the .LONGFILENAME extanded attribute if it exists
                4) Use a name derived from Inode and sector number
_______________________________________________________________________________

 MB             Megabytes, 10^6 = 1 000 000 bytes (decimal megabyte)
 MiB            MebiBytes, 2^20 = 1 048 576 bytes (binary  megabyte)
                For an explanation of the units see "IEC units"
_______________________________________________________________________________

 MBR            Master Boot Record
                The first sector on the physical disk, located at PSN 0 =
                Cylinder 0, Head 0, Sector 1.
                It contains the initial boot code loaded by the BIOS into RAM
                for execution, and the main partition table that holds the
                primary partitions and the start of the chain of extended boot
                records (EBR).
_______________________________________________________________________________

 mcs-number     A value that can be specified as decimal, octal or hexadecimal
 MCS            using units of Gigabytes (g), Megabytes (m), Kilobytes (k),
                Cylinders (c), Heads (h) or Sectors (s)
                The syntax specification for such a number is:

                        [0x|0o|0n|0t]nnnnnn[,g|m|k|c|h|s]

                A 0x prefix indicates hexadecimal format, 0o is octal and the
                0n, 0t or no prefix at all indicates a decimal number value.
                The number can have any number of digits, but should fit in a
                32 bit unsigned value. The default unit often is 'm' for MiB.
                Heads and Tracks are exact synonyms and lead to the same value.

                Note that specified units may not be useful in some contexts
                and might be ignored. The k,m and g unit will cause incorrect
                multipliers when used with non sector based values, example:
                The value "1,k" results in "2" (sectors) and NOT 1024!
                The geometry related units will use the geometry for the
                object in question (store, usually the current object).
_______________________________________________________________________________

 Medium         Partionable medium
 Media          Any device or object that can be accessed by DFSee and that may
 Mount          be subdivided using industry-standard partitioning schemes.

                The most common media found are the physical disks in a system,
                but virtual (in memory) disks or RAW imagefiles can be used as
                partionable media in DFSee as well, making them available as
                'disks' and allowing all DFSee operations on these disks and
                the partitions on them.

                By default, DFSee will 'mount' all physical disks present
                at startup, and you can use the MOUNT and UNMOUNT commands
                or corresponding menu-items to change that. The MEDIA command
                and corrsponding menu item display all mounted media.
_______________________________________________________________________________

 MFT            Master File Table
                The master index in an NTFS filesystem that has one (or more)
                descriptive records for every file in the filesystem, including
                the MFT itself and other system areas like the boot record.
                When the NTFS volume holds a lot of files, this MFT can become
                very large (like 20MiB on a 4GiB system partition).
_______________________________________________________________________________

 MFT copy       A copy of the first 16 (most important) MFT records describing
                all the NTFS system files including Root directory.
                DFSee will attempt to use that copy if the base MFT file seems
                to be damaged.
_______________________________________________________________________________

 MFT record     A record (typically 2 sectors) holding the key information
                about a file in NTFS. It has filename, size, date and time
                information, security info and allocation information about
                the file in question.
_______________________________________________________________________________

 Mixed string   A string, usually a parameter for a command, that may contain
                mixed ASCII, HEXADECIMAL and UNICODE parts. Without quoting
                the contents will be interpreted as ASCII, with single quotes
                it will be hexadecimal digit pairs and text within double-
                quotes will be translated to UNICODE. A complex example:

                   string'09'with tab'20 20 20'spaces" and some unicode"

                   ASCII      ASCII             ASCII
                         HEX            HEX                 UNICODE

                Usage examples, see the FIND and EDIT command (DFSCMDS.TXT)
_______________________________________________________________________________

 NTFS           New Technology File System
                The new (journalling) filesystem introduced with Windows-NT.
                It has many of the same improvements over FAT as HPFS, but has
                a totally different internal structure. It also adds security
                information and compression and is expandable by defining new
                stream-types. Several versions exist that added specific
                features to the original implementations.
_______________________________________________________________________________

 Partition      An area on a physical disk that holds a single logical
                filesystem like FAT, HPFS, IBM BootManager, NTFS etc.
                There is an index to find partitions in the form of a
                set of partition tables in the MBR/EBR chain.
_______________________________________________________________________________

 Part-tables    When dividing your harddisk space into partitions, the Operating
 explanation    Systems can use different filesystems within the partitions.
                These filesystems are FAT, FAT32, HPFS, NTFS and so on ...

                To make it a little easier to find out which filesystem is being
                used, there is an additional TYPE value in the partition table.
                This 'system-type' or 'partition type' or whatever it is called
                is a numeric value 0..255 often written in hexadecimal format so
                the range is 0x00 through 0xff.

                Some well-known and often used types are:

                0x06  FAT
                0x0b  FAT32
                0x07  HPFS or NTFS
                0x0a  IBM BootManager
                0x83  Linux EXT2

                Partitions that are directly defined in the first partition table
                (in the Master Boot Record = MBR) are called PRIMARY-PARTITIONS.

                So far it sounds rather simple, but there is another complication:
                Because a partition table can only hold information for FOUR
                partitions, you need something special if you want to have more.
                To do this, a special TYPE called EXTENDED-PARTITION is used that
                has the system-type value 0x05. So:

                0x05  Extended-partition

                The extended partition is really just a primary partition, of
                type 0x05 that can be further divided into small chunks called
                LOGICAL-PARTITIONS. The first type 0x05 (or 0x0f) partition
                defined in the MBR is often called the EXTENDED-CONTAINER.

                The extended partition itself contains another partition table,
                and that describes the TWO partitions inside this extended. ONE
                is a 'logical-partition' with any of the types mentioned above,
                like FAT, HPFS etc., and the other is again an EXTENDED-PARTITION.

                In this way the original EXTENDED-PARTITION can be subdivided
                into many smaller areas where each has a partition type such
                as 0x06, 0x07 and so on. (the logical-partition)

                This is often called the 'chain' of extended partitions, because
                each one 'points' to the next one. Because the tables are in
                MBR and EBR sectors, the term MBR/EBR chain is used too.

                Another way of saying this, is that every LOGICAL-PARTITION is
                really made up of an enclosing EXTENDED-PARTITION of type 0x05
                and the real (smaller) partition inside it with any of the
                filesystem related types like 0x06, 0x07 and so on.

                In most partitioning tools (like DFSee) these EXTENDED-PARTITIONS
                with type 0x05 are not shown in the normal partition list, which
                makes it more readable.

                Using "part -e -p-" will show ONLY the EXTENDED-PARTITIONS and
                using "part -e" will show them all. This will clearly show you
                that each logical really has two definitions with slightly
                differing sizes.

                Now, after understanding all this, here is the next complication
                (thanks to Microsoft):

                Starting with Windows95 OSR2, logical partitions can also use an
                EXTENDED-PARTITION with type 0x0f instead of 0x05!  It serves the
                same purpose, and the main reason for Microsoft to use it is to
                know that this is a LARGE (larger than 8GiB or so) partition that
                requires a different disk device driver ...
                I consider this a prime example of bad design!

                These partitions of type 0x0f are sometimes called "Extended-X"
                or "ExtendedBig" or, in MS FDISK terms "large disk support"

                Apart from the LARGE version of 0x05 being 0x0f, there is also
                a LARGE version of 0x0b being 0x0c for large FAT32 partitions.
_______________________________________________________________________________

 PDn            Partitionable Disk (number), or disk-id
 did            A numbering of partitionable media in a system, starting with 1.
                It is listed as the second column 'PD' in the 'part' display.
                This numbering in DFSee is also used for the virtual disks that
                can be created. The PD is often used as a parameter in the
                DFSee commands to explicitly choose a disk to work on.
_______________________________________________________________________________

 P-Geo          Physical geometry
                This is the geometry reported by the disk (or disk subsystem).
                It is for reporting only, DFSee does not use P-Geo in any way
_______________________________________________________________________________

 pid            Partition id
                A numbering of all the partitions (and freespace) areas on
                all the physical disks recognized by DFSee.
                It is listed as the first column 'id' in the 'part' display.
                This is an ongoing numbering over all disks, the same number
                also identifies any freespace that might be just BEFORE the
                partition with this pid. A freespace area after the last
                partition will have its own unique number (fid).
_______________________________________________________________________________

 Primary        A partition that is listed is the partition table in the MBR.
 partition      By convention these partitions start at the beginning of
                a disk cylinder (Head-0, sector 1) except for the very first
                partition that starts at Head-1, sector 1 to leave room for
                the MBR itself (and possibly other stuff, see Track-0 area)
_______________________________________________________________________________

 PSN            Physical Sector Number
                This is the zero-based, unsigned 32-bit, number for a
                sector on a physical disk. Addressing on a disk using
                PSNs is often referred to as Relative Block Addressing
                (RBA) or Logical Block Addressing (LBA)
_______________________________________________________________________________

 Radix (mask)   This is a configuration value that can be set using the -H
                switch or the "set radix" command, and controls the default
                number radix being HEX or decimal for specific classes of
                input values. (Displayed output is NOT affected by the radix)

                A "1" bit in the RADIX mask indicates HEX, and "0" is Decimal.

                Classes defined for DFSee, and defaults:
                   1  =  Standard class                  (DEC)
                   2  =  mcs-numbers ,s unit specified   (HEX)
                   4  =  mcs-numbers any other units     (DEC)
                   8  =  DFSee sector number,  no unit   (HEX)
                  16  =  DFSee size values,    no unit   (DEC)
                  32  =  DFSee partition type, no unit   (HEX)

                For the RADIX value adding the numbers results
                in a Radix value of 42 (or 0x2a)
_______________________________________________________________________________

 Recursion      See 'Recursion'
_______________________________________________________________________________

 Retries        Retries to read the contents of a sector from a store.
                Displayed using the 'store' command. (see 'Attempts')
_______________________________________________________________________________

 Sector         512 bytes of data (although other sizes exist!)
                This is the smallest amount of data manipulated by the
                disk subsystems and is also the basic allocation unit
                for the HPFS filesystem
_______________________________________________________________________________

 Sector list    A list of sector numbers (LSN) or LsnInfo values that can be
                manipulated as a whole with commands like list, export, import,
                getbs, fixbs, dirfind, delfind, recover etc.
                The size of the list is 25000000 entries (2.5 million) when
                enough memory is available, or about 300000 otherwise.
_______________________________________________________________________________

 Shortname      The leading part of a filename, as contained in an HPFS fnode
 (hpfs)         and useful for undelete. The maximum length is 15 characters
_______________________________________________________________________________

 Shortname      The classical 8.3 version of a file/directory name that is
 (VFAT)         kept in a VFAT directory, alongside the long filename (LFN)
_______________________________________________________________________________

 SLT            Sector/Cluster Lookup Table
                An array of information about sectors or groups of sectors,
                containing the type of the sector(s) and the LSN of a
                directly related sector (usually an Fnode).
                It is currently implemented for HPFS only.
_______________________________________________________________________________

 Store          A collection of numbered sectors, being the basis for ALL
                DFSee commands to work on. A store can be representing:
                - A partitionable medium, usually in FDISK mode (cmd DISK/WALK)
                - A partition on a disk, with a FS mode like HPFS   (cmd PART )
                - A volume opened directly, with a mode like HPFS   (cmd VOL  )
                - An image file opened for analysis                 (cmd IM   )

                DFSee currently uses 3 stores (display with "store" cmd):

                0: The system store, used by DFSee internally
                1: User store number 1 (the CURRENT store at startup)
                2: User store number 2 (the alternate store at startup)

                The CURRENT store is the one almost ALL commands work on.
                The alternate store can be used as the second store to
                work with for commands like CLONE and COMP where one store is
                the FROM object and the other the TO object for the operation.

                Note: The concept of the stores, and their usage is mostly
                      hidden from the end-users experience by the commands
                      and menu-items that use them ...
_______________________________________________________________________________

 Superblock     Usually the most important data structure in a filesystem,
                with the information to find the rest of the data.
                There may be more of them, usually exact duplicates in
                other location to improve redundancy and recoverability.

                Known under this name in HPFS, JFS, EXT2/3 and various UNIX FS
_______________________________________________________________________________

 Spareblock     A secondary superblock used by the HPFS filesystem.
 HPFS           All 'static' information, that does not normally change
                during a normal session, is kept in the real 'Superblock'
                which is only written by FORMAT, CHKDSK and perhaps DFSee :-)
                Information that may change during a session is stored in
                the 'Spareblock', read and written by the HPFS.IFS driver.
_______________________________________________________________________________

 Symbolic SN    Symbolic sector number
 or 'SSN'       Used by many DFSee commands as a parameter representing
                a sector number in one of several forms:

                - A hexadecimal value with 1 upto 8 HEX digits
                - A value from the sector list addressed as '.NNN'
                - 'this' or '.' representing the current sector
                - 'up'          representing the 'up in hierachy' sector
                - 'down'        representing the 'down in hierachy' sector
                - 'xtra'        representing the 'extra' sector number
_______________________________________________________________________________

 S-Geo          System Geometry
                Used by the DFSee low-level DISK read and write routines.
                It is usually the same as the logical geometry, but does NOT
                change when the logical geometry is changed with the GEO cmd
_______________________________________________________________________________

 Track-0 area   A small, normally unused, area at the beginning of the disk,
                between the MBR and the first primary partition.
_______________________________________________________________________________

 Track size     The number of sectors that are in one 'track' on the disk,
                using a specific geometry. Also called 'sectors per track'.
                Most geometries used have a value of 63 sector per track.
_______________________________________________________________________________

 Truncate       Make a filesystem in a partition on a disk smaller, usually
                to allow creation of another partition.
                Typical use: create freespace to install a new operating system
_______________________________________________________________________________

 VCU            Volume Conversion Utility
                A program used with (the installation of) the LVM enabled
                versions of the OS/2 Operating System like eCS and WSeB.
                It will create default LVM information-sectors for all the
                existing partitions on all physical disks. The partitions
                will all be "LVM compatibility volumes" that have default
                volume, partition and disk names like [A1] and [D1].
                This can be maintained later using the LVM/LVMgui programs.
_______________________________________________________________________________

 VFAT           An extension to the regular FAT directory entries that allows
                storage of long-filenames (LFNs) as well as the classic 8.3
                short version of those names. Used mainly by newer Windows
                versions, beginning with Windows95. It can be used on any
                FAT filesystem, FAT12 (diskette), FAT16 and FAT32.
_______________________________________________________________________________

 Virtual disk   A disk that can be used just like other partitionable medium
 (DFSee)        in DFSee but that only exists within DFSee memory.
                It can be created using the 'MOUNT' command, and is intended
                for experimenting and complex recovery scenarios.
                Note: This is not the same as a 'RAMDISK' used with DOS
_______________________________________________________________________________

 Volume         A logical volume as seen by the active Operating System,
                with an associated logical drive-letter.
                It can be either a hard-disk partition with a filesystem
                recognized and mounted by the Operating System, or some
                other storage-medium like a Floppy disk or CDROM.
                Note: Network drives or other "virtual" filesystems can also
                      be referred to as volumes. However, DFSee can not access
                      them because such devices usually cannot be accessed
                      using low-level "open volume" (DASD) methods.

                Note: The term "Volume" is also used by WSeB, eCS and new OS/2
                      systems that use the Logical Volume Manager (LVM).
                      In this case the above still applies, but there is more
                      to LVM-volumes than this, like disk-spanning etc.
                      For LVM systems think of a volume as another abstraction
                      layer, on top of the bare 'partitions'.
                      There is usually a one to one relationship between a
                      volume and a partition, but a volume CAN be associated
                      with more than one.
_______________________________________________________________________________

 ----------------------------[ www.dfsee.com ]-------------------------------

