Provided by: openafs-client_1.6.0-1_i386 bug

NAME

       tapeconfig - Defines parameters for tape devices and backup data files

DESCRIPTION

       The tapeconfig file defines basic configuration parameters for all of
       the tape devices or backup data files available for backup operations
       on a Tape Coordinator machine. The file is in ASCII format and must
       reside in the local /var/lib/openafs/backup directory. The instruction
       for each tape device or backup data file appears on its own line and
       each has the following format:

          [<capacity> <filemark_size>] <device_name> <port_offset>

       where

       <capacity>
           Specifies the capacity of the tapes used with a tape device, or the
           amount of data to write into a backup data file. The Tape
           Coordinator refers to this value in two circumstances:

           ·   When the capacity field of a tape or backup data file's label
               is empty (because the tape has never been labeled). The Tape
               Coordinator records this value on the label and uses it when
               determining how much data it can write to the tape or file
               during a backup dump or backup savedb operation. If there is
               already a capacity value on the label, the Tape Coordinator
               uses it instead.

           ·   When the -size argument is omitted the first time the backup
               labeltape command is used on a given tape or file.  The Tape
               Coordinator copies this value into the label's capacity field.

           The Tape Coordinator uses this capacity value or the one on the
           Backup System tape label to track how much space remains as it
           writes data to a tape or backup data file. The appropriate value to
           record for a tape depends on the size of the tapes usually used in
           the device and whether it has a compression mode; for suggested
           values, see the OpenAFS Administration Guide chapter on configuring
           the Backup System. If using a value obtained from the fms command,
           reduce it by 10% to 15% before recording it in the file.

           For a backup data file, it is best to provide a value that helps
           the Tape Coordinator avoid reaching the end-of-file (EOF)
           unexpectedly. Make it at least somewhat smaller than the amount of
           space available on the partition housing the file when the dump
           operation begins, and never larger than the maximum file size
           allowed by the operating system.

           Specify a (positive) integer or decimal value followed by a letter
           than indicates units, with no intervening space. In a decimal
           number, the number of digits after the decimal point must not
           translate to fractions of bytes. The maximum acceptable value is
           2048 GB (2 TB). The acceptable units letters are as follows; if the
           letter is omitted, the default is kilobytes.

           ·   "k" or "K" for kilobytes (KB).

           ·   "m" or "M" for megabytes (MB).

           ·   "g" or "G" for gigabytes (GB).

           ·   "t" or "T" for terabytes (TB).

           If this field is omitted, the Tape Coordinator uses the maximum
           acceptable value (2048 GB or 2 TB). Either leave both this field
           and the <filemark_size> field empty, or provide a value in both of
           them.

       <filemark_size>
           Specifies the size of a tape device's filemarks (also called end-
           of-file or EOF marks), which is set by the device's manufacturer.
           In a dump to tape, the Tape Coordinator inserts filemarks at the
           boundary between the data from each volume, so the filemark size
           affects how much space is available for actual data.

           The appropriate value to record for a tape depends on the size of
           the tapes usually used in the device and whether it has a
           compression mode; for suggested values, see the OpenAFS
           Administration Guide chapter on configuring the Backup System. If
           using a value obtained from the fms command, increase it by 10% to
           15% before recording it in the file.

           For backup data files, record a value of 0 (zero). The Tape
           Coordinator actually ignores this field for backup data files,
           because it does not use filemarks when writing to a file.

           Use the same notation as for the <capacity> field, but note that
           the default units is bytes rather than kilobytes. The maximum
           acceptable value is 2048 GB.

           If this field is empty, the Tape Coordinator uses the value 0
           (zero). Either leave both this field and the <capacity> field
           empty, or provide a value in both of them.

       <device_name>
           Specifies the complete pathname of the tape device or backup data
           file. The format of tape device names depends on the operating
           system, but on UNIX systems device names generally begin with the
           string /dev/. For a backup data file, this field defines the
           complete pathname; for a discussion of suggested naming conventions
           see the description of the "FILE" instruction in butc(5).

       <port_offset>
           Specifies the port offset number associated with this combination
           of Tape Coordinator and tape device or backup data file.

           Acceptable values are the integers 0 through 58510 (the Backup
           System can track a maximum of 58,511 port offset numbers).  Each
           value must be unique among the cell's Tape Coordinators, but any
           number of them can be associated with a single machine. Port offset
           numbers need not be assigned sequentially, and can appear in any
           order in the tapeconfig file. Assign port offset 0 to the Tape
           Coordinator for the tape device or backup data file used most often
           for backup operations; doing so will allow the operator to omit the
           -portoffset argument from the largest possible number of backup
           commands.

PRIVILEGE REQUIRED

       Creating the file requires UNIX "w" (write) and "x" (execute)
       permissions on the /var/lib/openafs/backup directory. Editing the file
       requires UNIX "w" (write) permission on the file.

EXAMPLES

       The following example tapeconfig file configures three tape devices and
       a backup data file. The first device has device name /dev/rmt/0h, and
       is assigned port offset 0 because it will be the most frequently used
       device for all backup operations in the cell. Its default tape capacity
       is 2 GB and filemark size is 1 MB. The /dev/rmt/3h drive has half the
       capacity but a much smaller filemark size; its port offset is 3. The
       third device listed, /dev/rmt/4h, has the same capacity and filemark
       size as the first device and is assigned port offset 2. Port offset 4
       is assigned to the backup data file /dev/FILE, which is actually a
       symbolic link to the actual file located elsewhere on the local disk.
       The Tape Coordinator writes up to 1.5 GB into the file; as recommended,
       the filemark size is set to zero.

          2G 1M /dev/rmt/0h 0
          1g 4k /dev/rmt/3h 3
          2G 1m /dev/rmt/4h 2
          1.5G 0 /dev/FILE 4

SEE ALSO

       backup_addhost(8), backup_dump(8), backup_labeltape(8),
       backup_savedb(8), butc(8), fms(8)

COPYRIGHT

       IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

       This documentation is covered by the IBM Public License Version 1.0.
       It was converted from HTML to POD by software written by Chas Williams
       and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.