Managing Serviceguard Eighteenth Edition, September 2010

upgrade can also be done any time one system needs to be taken offline for hardware
maintenance or patch installations.
This method is among the least disruptive, but your cluster must meet both general
and release-specific requirements. See “Guidelines for Rolling Upgrade” (page 450).
Rolling Upgrade Using DRD
DRD stands for Dynamic Root Disk. Using a Dynamic Root Disk allows you to perform
the update on a clone of the root disk, then halt the node and reboot it from the updated
clone root disk.
A rolling upgrade using DRD is like a rolling upgrade, but is even less disruptive
because each node is down for a shorter time. It is also very safe; if something goes
wrong you can roll back to the original (pre-upgrade) state by rebooting from the
original disk.
This method is the least disruptive, but you need to make sure your cluster is eligible;
see“Restrictions for DRD Upgrades” (page 449).
You can obtain the DRD software free from www.hp.com/go/drd.
Restrictions for DRD Upgrades
• Upgrade using DRD is supported only on HP-UX 11i v3.
• You must use the DRD software released with the September 2009 release of
HP-UX 11i v3 or later.
You can obtain the DRD software free from HP (see “Rolling Upgrade Using DRD”
); you do not have to upgrade the operating system itself, so long as you are running
11i v3.
• The cluster must meet both general and release-specific requirements for a rolling
upgrade; see “Guidelines for Rolling Upgrade” (page 450).
• Not all paths that are supported for rolling upgrade are supported for an upgrade
using DRD, and there are additional requirements and restrictions for paths that
are supported; see the Release Notes for the target version of Serviceguard.
Non-Rolling Upgrade
In a non-rolling upgrade, you halt the cluster before upgrading HP-UX (if necessary)
and the Serviceguard software.
This method involves cluster down time, but allows for a broader range of upgrades
than rolling upgrade. For example, you will need to do a non-rolling upgrade, or a
migration with cold install, if you are upgrading from an older release of Serviceguard
than rolling upgrade supports (see the Release Notes for the target version of
Serviceguard for the specific rolling upgrade requirements).
Types of Upgrade 449