Forum Discussion
JRahm
Oct 02, 2013Admin
Operationally, I am a fan of this process:
- Sync both systems, create archives, and ftp them offbox somewhere, then freeze all configuration changes for the duration of the upgrade window
- Take snapshots of current system and application performance and availability
- Upgrade the standby unit and fail over to it
- Take new snapshots of current system and application performance and availability and compare to the ones taken before the upgrade, failing back if there are issues that can't immediately be addressed. If all is well, then proceed.
- Upgrade the now standby unit and fail back over to it
- Take another set of snapshots and compare to previous to make sure both units in the pair took the upgrade well.
- Watch for anomalies over the course of several days, then unfreeze the configuration changes.
The benefit of a config freeze during the upgrade process is it is super simple to fall back, just boot back into the previous version bootslot on the standby and then fail over.