A tape set consists of one or more backup tapes produced on a given archive device. The first tape set you specify must be large enough to hold the full backup of the catalog store, including any non-SAP Sybase IQ data in the catalog store.
Digital Linear Tape (DLT) is the preferred magnetic tape data storage medium. If it is supported for your platform, use DLT for tape backups. BACKUP can also support 4mm and 8mm Digital Data Storage (DDS) tape drives, and stacker devices that support multiple tape devices.
BACKUP does not support jukeboxes or robotic loaders. Use a third-party media manager for these items.
Use multiple tape drives for large database backups. The TO clause identifies each tape drive device. The SIZE option sets the data capacity for each tape. The STACKER option indicates a backup to a multi-tape stacker device, and the number of tapes in the device. All tapes in a given stacker device must be the same size.
mt -f <tape device> statusIf the command returns a block-size greater than 0, the device is set for fixed-length blocks. To change the tape drive to variable-length blocks, use this or other appropriate OS shell command:
mt -f <tape device> defblksize 0
| Platform | Description |
|---|---|
|
Solaris |
Insert the letter n for no rewind after the device name:
/dev/rmt/0n |
|
AIX |
Set the numeric value that follows the
logical name of the tape drive for an no rewind
setting:
/dev/rmt0.1See the AIX documentation for specific settings. |
|
HP-UX |
Use 0m
to specify the default tape mechanism and n for no
rewind:
/dev/rmt/0mn
|
Windows does not support rewind or no rewind devices. SAP Sybase IQ requires variable-length devices, but does perform additional processing to accommodate fixed-length tape I/O on Windows.
Because SAP Sybase IQ does not support tape partitioning, do not use another application to format tapes for BACKUP or RESTORE operations. On Windows, the first tape device is \\.\tape0, the second is \\.\tape1, and so on.
To indicate the first tape device, use \\\\.\\tape0, \\\\.\\tape1 for the second device, and so on. If you omit the extra backslashes, or otherwise misspell a tape device name, and write a name that is not a valid tape device on your system, SAP Sybase IQ interprets this name as a disk file name.
Use the SIZE parameter to set the data capacity for each tape. The SIZE value can be less than or greater than the default tape size. If you omit the SIZE parameter for an unattended backup, the entire backup must fit on one tape.
TO '/dev/rmt/0n' SIZE 10000000 TO '/dev/rmt/2n' SIZE 15000000Use separate lines for each TO clause, not a comma-delimited list.
During backup, when the amount of information exceeds the tape capacity or reaches the value specified by the SIZE parameter, BACKUP closes the current tape. For attended and unattended backups that specify the SIZE and STACKER parameters, SAP Sybase IQ waits for the stacker device to auto-load the next tape, then resumes the backup.
If the backup exceeds the tape capacity in an attended backup without a STACKER device, BACKUP prompts you to mount a new tape. If the backup exceeds the tape capacity in a unattended backup without a STACKER device, the backup fails.
SAP Sybase IQ does not rewind tapes before using them. Set the tapes to the correct starting point before you put them in the tape device. If you use a rewinding device, tapes are rewound after backup. If your tape device automatically rewinds tapes, position the tape so that a subsequent backup does not overwrite any information on the tape.
If SAP Sybase IQ cannot open an archive device, the server waits for 10 seconds and tries again. These attempts continue indefinitely, until the operation succeeds or is terminated. A message is written to the server .stderr file. There is no console notification that the server cannot open the archive device.
Position the tape to the start of the IQ data. RESTORE does not reposition the tape for you. Use the same number of tape drives for the restore you used to create the backup.