Designing High Availability Solutions with HP Serviceguard and HP Integrity Virtual Machines

When creating VMs:

• Consider how using uniprocessor vs. multiprocessor VMs can affect the overall performance of CPU resources on

the VM host. The use of multi-processor VMs may require the tuning of Serviceguard node timeout and heartbeat

interval parameters in some instances to avoid false detection of Serviceguard node failures. The only way to do

this tuning is through “trial and error”.

• Avoid over-allocating memory for VMs to prevent memory management interrupts and to allow the remaining memory

on the VM host to be used by other VMs. Memory sizes will vary based on VM guest application requirements. The

HP Integrity Virtual Machines installation, configuration, and administration guide and the hp integrity virtual machines

release notes (Integrity VM documentation available at

www.hp.com/go/hpux-hpvm-docs) have sections describing

VM host system requirements that can help you determine the amount of memory that will be required for a VM host

based on the memory sizes and number of VM guests that will be running on the VM host. Typical memory

requirements are:

– HP-UX 11i v2 VM guests use 1.5 GB (at least 2 GB of memory is required when using the Serviceguard Storage

Management Suite A.02.00)

– HP-UX 11i v3 VM guests use 3 GB

– Linux RH4 VM guests use 1.5 GB

– Linux SLES10 VM guests use 1.5 GB

– Windows Server VM guests use 1 GB

For virtual mass storage:

• Consider the performance tradeoffs for each storage type (for example, file, logical volume, physical disk) as well

as the flexibility of managing the storage used by the VMs.

• The best disk I/O performance for VMs is generally achieved by mapping virtual disks directly to physical disks

(or LUNs). Note that VM as Serviceguard node configurations require physical disk backing stores due to their

VM-specific storage implementation.

For virtual networking:

• HP APA can be used to add network capacity to VMs, as well as provide network redundancy.

• Maintain data center network topologies and their primary functions (for example, primary/standby LANs) by

appropriately mapping vswitches to VM host NICs to preserve existing network functionality and performance.

When tuning VMs:

• The guest OS for a given VM should be tuned for the specific application running within the VM as recommended

by the application provider.

Software upgrades

Serviceguard has a rolling upgrade capability that allows for updating Serviceguard and operating system software

within specific version ranges while allowing the cluster to remain operational. Rolling upgrades can be performed in

both VM as Serviceguard package and VM as Serviceguard node configurations by moving either the VM guest or

application packages to an adoptive node and performing an upgrade on the node that was previously running the

packages. Once the upgrade has been completed, the packages can be moved back to the upgraded node and the

process repeated for the remaining nodes in the cluster.

There is no rolling upgrade procedure for cmappserver. There is only one image of the virtual machine operating

system and applications so, when cmappserver is updated, it cannot maintain the monitoring of the applications.

Also, it cannot continue to exchange heartbeats with the various cmappmgr instances.

Since moving from earlier Integrity VM versions to Integrity VM B.04.00 (and later) requires an upgrade of the VM

host from HP-UX 11i v2 to 11i v3, there are several restrictions that need to be considered and procedures followed

to successfully complete this upgrade. This information is available in a technical white paper titled Upgrading to

Integrity VM Version 4.0 from 3.X (