VM /ETC

Posts Tagged ‘HA’

Admins of heavily consolidated VMware VI 3 Clusters should make plans as soon as possible to download Update 5 of VMware vCenter Server to take advantage of increased performance and scalability. The latest update to vCenter 2.5 was released on July 10 and boasts improvements to support fail over management of up to 80 VMs per ESX/ESXi host in a HA (High Availability) Cluster.

The following details were taken from the VMware VirtualCenter 2.5 Update 5 Release Notes:

What’s New

Support for High Consolidation in VMware HA Clusters – VirtualCenter 2.5 Update 5 includes significant performance and scalability improvements to VMware HA. Use VirtualCenter 2.5 Update 5 for environments with more than 35 virtual machines (VMs) per host in an HA cluster.

For information on the ESX Server host settings required for this scalability improvement, see ESX Server host settings required for environments with up to 80 virtual machines per host in an HA Cluster (KB 1012002).

Upgrading or Migrating to VirtualCenter 2.5 Update 5

This release supports upgrading from VirtualCenter 1.4.1, VirtualCenter 2.0.2 (including Update 1, Update 2, Update 3, Update 4, and Update 5), VirtualCenter 2.5, VirtualCenter 2.5 Update 1, VirtualCenter 2.5 Update 2, VirtualCenter 2.5 Update 3, or VirtualCenter 2.5 Update 4, to VirtualCenter 2.5 Update 5. Review the detailed upgrade and migration instructions and guidelines that are provided in the Upgrade Guide.

Following the above link to KB 1012002 explains that upgrading vCenter 2.5 to U5 is just the start. VI 3 admins also need to make some additional configurations on ESX/ESXi hosts to achieve the 80 VMs per host improvements.

“Starting with the VirtualCenter 2.5 Update 5 release, an ESX Server host in an HA cluster can support up to 80 virtual machines. For all virtual machines to power on on other hosts in the cluster, if hosts within the failover capacity limit fail, you need to ensure that the following parameters in the ESX Server hosts are set with the following values:

Read the rest of this entry »

So, who wants free VMware High Availability? That’s the title of a post created by Leo Raikhman on his Leo’s Ramblings blog. In this post, Leo has published the steps and scripting necessary to simulate VMware’s VI3 High Availability (HA) feature. Leo’s script works without VirtualCenter (VC), so VMware customer’s who have not implemented VC can manually create “HA -like” awareness between 2 ESX hosts. If one of the ESX servers goes offline then the virtual machines (VMs) are auto restarted on the other host. Of course, the VMs must be created on shared storage for this to work.

Before considering this script as a replacement understand the major differences between VirtualCenter HA and Leo’s HA:

• Leo’s script only works between 2 ESX hosts while VC HA can be configured with up to 32 ESX hosts as of VI 3.5 (actually using 32 host HA clusters is another topic, but it can be done)
• Leo’s script needs the ESX Service Console as written. It would need to be ported for the RCLI to work with ESXi. VC HA works with both ESX and ESXi
• VC provides a visual status for the health of your HA cluster via the VI Client
• VC HA provides HA fail over capacity for more than 1 ESX host at a time

I’ve held this post in my drafts because I wanted to try this configuration myself, but alas, I have never gotten around to it.  For those that can benefit from VC -less HA and give this script a test, let me (and Leo) know your results.

Leo’s post says: Read the rest of this entry »