Restoring After a Media Failure on the Primary Database Server

Table 44 summarizes the various scenarios for restoring data if the primary database server suffers media failure. The following issues are relevant:

• If chunks are mirrored, you can perform recovery just as you would for a standard database server that used mirroring.
• In cases where the chunks are not mirrored, the procedure for restoring the primary database server depends on whether the disk that failed contains critical media.

  If the disk contains critical media, the primary database server fails. You have to perform a full restore using the primary dbspace backups (or the secondary dbspace backups if the secondary database server was switched to standard mode and activity redirected). See Restarting After Critical Data Is Damaged.

  If the disk does not contain critical media, you can restore the affected dbspaces individually with a warm restore. A warm restore consists of two parts: first a restore of the failed dbspace from a backup and next a logical restore of all logical-log records written since that dbspace backup. For more information on performing a warm restore, see the IBM Informix Backup and Restore Guide. You must back up all logical-log files before you perform the warm restore.