REMOVABLE MEDIA INFORMATION 87/10/06
CARTRIDGE -- Cartridge Tape Usage Information
---------------------------------------------
A DOMAIN network may read and write data residing on cartridge tapes on a
DN550. Cartridges may be either ANSI labeled or unlabeled, with files of
ASCII, EBCDIC, or raw characters. Cartridge tape supports only 512 byte
blocks (although smaller may be specified) and fixed length record format
only. System bootable cartridge tapes are also supported.
The following general restrictions apply:
o You must perform the tape operations on the node to which the
cartridge drive is attached.
o Only one drive may be attached to any particular node.
The following commands are supplied for use with cartridge tapes:
o WBAK (WRITE_BACKUP) writes one or more object trees to a cartridge
'backup file'. Cartridge tapes written with this program may be
used for backup, or to interchange files with other DOMAIN
installations. Certain WBAK options are valid only for cartridge
tapes (-RETEN, -NO_EOT, -SYSBOOT).
o RBAK (READ_BACKUP) indexes or restores to disk the contents of a
backup file written with the WBAK command.
o RWMT (READ_WRITE_MAGTAPE) transfers files between disk and
cartridge. Use this command to interchange files with other,
non-DOMAIN installations.
o EDMTDESC (EDIT_MAGTAPE_DESCRIPTOR_FILE) creates and modifies
cartridge descriptor files for use with streams.
o CPBOOT (COPY_BOOT) may be used to create a bootable cartridge tape.
Help is available for all of these commands. Type 'HELP' followed by the
relevant command name for more information.
MAGTAPE -- Magnetic Tape Usage Information
------------------------------------------
A DOMAIN network may read and write data residing on 9-track magnetic tapes
formatted to a density of 1600 bits per inch. Tapes may be either ANSI
labeled or unlabeled, with files of ASCII, EBCDIC, or raw characters. The
following general restrictions apply:
- You must perform the tape operations on the node to which the tape
drive is attached.
- Only one tape drive may be attached to any particular node.
The following commands are supplied for use with magnetic tapes:
- WBAK (WRITE_BACKUP) writes one or more object trees to a magtape
'backup file'. Magtapes written with this program may be used for
backup, or to interchange files with other DOMAIN installations.
- RBAK (READ_BACKUP) indexes or restores to disk the contents of a
backup file written with the WBAK command.
- RWMT (READ_WRITE_MAGTAPE) transfers files between disk and magtape.
Use this command to interchange files with other, non-DOMAIN
installations.
- EDMTDESC (EDIT_MAGTAPE_DESCRIPTOR_FILE) creates and modifies magtape
descriptor files.
Help is available for all of these commands. Type 'HELP' followed by the
relevant command name for more information.
VOLID -- Automatic volume id generation for labeled tapes
---------------------------------------------------------
The RWMT (READ_WRITE_MAGTAPE) and WBAK (WRITE_BACKUP) commands provide three
ways to generate the volume id for labeled tapes:
1. The id may be supplied explicitly with the -VID option.
2. It may be generated automatically, as described below.
3. If no id is supplied, and if automatic volume id generation has not
been enabled, then the default volume id of spaces is used.
To enable automatic volume id generation, make sure the directory
`node_data/system_logs exists. In `node_data/system_logs, use the DM editing
capabilities to create a file called NEXT_VOLUME_ID. Place a 1-6 character
alphanumeric text string in this file. This is the string which will be used
as the volume id the next time a tape is to be labeled. When a labeling
operation occurs, the string is automatically updated by adding 1 to the
right-most non-space character of the string, and carrying to the left if the
character was "9" or "Z".
At software release 9.7 the above method of automatic labeling is suggested.
However, for backwards compatiblity if `node_data/system_logs/next_volume_id
is not found the volume id will be taken from /sys/tape/next_volume_id if it
exists.