Sybase 12.4.2 manual Backing up the right files, Restoring from a system-level backup, 392

Performing system-level backups

Backing up the right files

Required files	You must back up the following files:
	• SYSTEM dbspace file, typically named dbname.db.
	• The transaction log file, which is required for system recovery, typically
	named dbname.log
	• The IQ_SYSTEM_MAIN dbspace file, typically named dbname.iq
	• The IQ_SYSTEM_TEMP dbspace file, typically named dbname.iqtmp
	• Files for any additional dbspaces that have been added to
	IQ_SYSTEM_MAIN or IQ_SYSTEM_TEMP

Optional files

Keeping your backup list updated

Raw devices and symbolic links

It is a good idea to back up the ASCII message files such as dbname.iqmsg and the $ASLOGDIR/*.svrlog and $ASLOGDIR/*.stderr files. These files are not required. However, if problems occur during a restore, the .iqmsg file will prove that the database was shut down before the backup started.

These files may be useful in diagnosing the cause of the database failure you are recovering from. Be sure to make a copy before restoring, for use in later analysis.

It is critically important to add to your system backup specification any dbspaces that are added to the database, whether they are in SYSTEM, IQ_SYSTEM_MAIN, or IQ_SYSTEM_TEMP. If a dbspace is added several months down the road, or after some turnover in your organization, you may miss this step.

To ensure that you are backing up all the files you need, use a script for system- level backups. In the script, before starting the backup, compare a select from SYSFILES (for the system dbspaces) and from IQSYSFILES (for the IQ dbspaces) to a list of dbspaces known to be in the system backup specification.

If your database files are on raw devices, be sure your system backup is backing up the raw device contents, not just the NAME of the device in /dev/*.

If symbolic links are used for raw device names, as recommended, be sure the system backup utility follows the symbolic link and backs up the device.

Restoring from a system-level backup

If you must restore from a system-level backup, you must ensure that database server is shut down, just as it was during the backup. See “Shutting down the database” on page 391 for details.

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