A rolling upgrade is a method of upgrading the clusters in a system. A rolling upgrade has two main phases. In Phase 1, the installer upgrades the kernel packages and in Phase 2, the installer upgrades Symantec Cluster Server (VCS) and VCS agent packages. Since the process rolls over in phases, it is termed as a rolling upgrade. You can perform a rolling upgrade to minimize the downtime for the cluster. The advantage of this method is that it ensures that the service groups that are online, remain online throughout the upgrade process. You can plan the failover and selectively upgrade systems. This ensures that the failover service groups are never offline.
The rolling upgrade process is as follows:
During Phase 1, the only downtime is the time required for the service groups to failover. The downtime is limited to the applications that are failed over and not the entire cluster.
During Phase 2, downtime occurs when the VCS engine HAD restarts, but this does not include application downtime.
Symantec provides both a script-based and a web-based installer to perform a rolling upgrade of Storage Foundation and High Availability (SFHA).
For more information about the rolling upgrade process, see:
Symantec Storage Foundation and High Availability documentation for other releases and platforms can be found on the SORT website.