8.5.13 Rolling Back Updates

A backup enables you to roll back updates, regardless of whether the update failed or succeeded. This backup is stored on the inactive system partition, as described in "Backing up Exadata Database Servers Before Planned Maintenance".

When rolling back an update, the update utility performs the following actions:

• Shuts down the stack and domU’s.
• Deactivates the active system partition, and activates the inactive system partition.
• Restores /boot from the inactive partition.
• Updates the grub boot-loader.

Having only one inactive system partition limits the rollback options to only the previous active image.

Note:

• For systems being updated to Oracle Linux 6, a backup must be performed before proceeding with the update. The backup is automatic when updating LVM-enabled systems from Oracle Linux 5 to Oracle Linux 6.
• Database servers running as Oracle VM Server (dom0) switch between LVDbSys2 and LVDbSys3 as the active system partition when rolling back.
• Database servers running as Oracle VM (domU) have smaller sizes for LVDbSys1 compared to physical hardware deployments.

Example 8-15 Rolling back an update using patchmgr

[root@pmserver ]# ./patchmgr --dbnodes dbs_group --rollback

--dbnodes specifies the list of database nodes to be updated.

--rollback specifies the rollback action.

For more options see the update utility’s built-in help.

Note:

Firmware updates are not rolled back when rolling back to a previous image. The Oracle Exadata System Software releases support later firmware releases. After rolling back, run the following commands to apply older firmware versions when needed:

/etc/init.d/lsidiag stop

/etc/init.d/lsi_mrdsnmpd stop

/opt/oracle.cellos/CheckHWnFWProfile -action updatefw -mode exact

The last command only applies to releases 11.2.3.3.0 or later.