Sybase 12.4.2 - Manual (Page 409)

CHAPTER 11 Backup and Data Recovery
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TO ’/dev/rmt/0n’
TO ’/dev/rmt/1n’
WITH COMMENT ’Jan 18 full backup of asiquser’
The Catalog Store is backed up first, to /dev/rmt/0n. The IQ Store is backed up
next, to both tapes.
Example 2 —
Incremental backup To make an incremental backup of the same database, this time using only one
tape device, issue the command as follows:
BACKUP DATABASE
INCREMENTAL
TO ’/dev/rmt/0n’ SIZE 150
WITH COMMENT ’Jan 30 incremental backup of asiquser’
An example of how to restore this database from these two backups is provided
later in this chapter.
Recovery from errors during backup
There are two likely reasons for a failed backup: insufficient space, or
hardware failure. Problems with third party software could also cause a failure.
Checking for backup space
BACKUP uses the STACKER and SIZE parameters to determine whether there
is enough space for the backup.
• For disk backups, if it decides that you have not provided enough space, it
fails the backup before actually writing any of the data.
• If it decides that there is enough space to start the backup, but then runs
out before it finishes (for example, if your estimate is incorrect, or if a user
in another application fills up a lot of disk space while your backup is in
progress), an attended backup prompts you to load a new tape, or to free
up disk space. An unattended backup fails if it runs out of space.
• If neither STACKER nor SIZE is specified, backup proceeds until it
completes or until the tape or disk is full. If you run out of space, an
attended backup prompts you to load a new tape, or to free up disk space;
an unattended backup fails.
Recovery attempts
If a backup fails, the backup program attempts to recover as follows: