Sybase 12.4.2 User Manual

CHAPTER 11    Backup and Data Recovery

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.

There are two likely reasons for a failed backup: insufficient space, or 
hardware failure. Problems with third party software could also cause a failure.

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.

If a backup fails, the backup program attempts to recover as follows: