I would like to know the best method for upgrading two Cisco ASA 5510's that are configured in active/standby mode. I don't want to take both units down for the upgrade, but upgrade one while the other is still active. I was thinking of the following:
1. Failover to Standby unit
2. Upgrade Primary unit's OS and ASDM
3. Once Primary is finished with upgrade, failback to primary and make it active
4. Then upgrade the Secondary unit
Does anyone see any problems with this method? Has anyone ever performed this type of upgrade whle keeping one unit online/active? Just want to minimize downtime.