VM-Host affinity

[rb51]

Hi all,

environment:

hosts running ESX4.1U2

We have to setup a VM-Host affinity rule to enforce licensing restricitions, whereby just a couple of VMs need to stay on just one specific host (SQL2000 licensing too costly to spread over another host(s)).

We are aware that this will not provide protection in case of host failure. Therefore the VMs will be powered off if the host fails.

I have got a couple of questions:

1) I will probably need to Enable Start and Stop Virtual Machines with the System on the specific host housing the VMs. If so what would be the impact of, let's say, restarting Service Management Agents or putting the host into Maintenance Mode???

2) Reading vSphere4.1 HA documentation it says that Manual Violations are not permitted. Does it mean that I cannot temporarily and manually vMotion the VM to another host in case? Do I need to drop the VM off the DRS Host Group before manually vMotioning it?

Comments are much appreciated

[Troy_Clavell · Accepted solution]

1) I will probably need to Enable Start and Stop Virtual Machines with  the System on the specific host housing the VMs. If so what would be the  impact of, let's say, restarting Service Management Agents or putting  the host into Maintenance Mode???

in an HA cluster the startup/shutdown options are ignored.  HA uses restart priorities.  Restarting the management agents will have no impact on any guests.  Affinity rules are DRS.  So, if you put the host in maintenance mode, you 'll need to manually vMotion the guest to another host and disable the rule temporarily.

2) Reading vSphere4.1 HA documentation it says that Manual Violations  are not permitted. Does it mean that I cannot temporarily and manually  vMotion the VM to another host in case? Do I need to drop the VM off the  DRS Host Group before manually vMotioning it?

see above.

[weinstein5]

I am assuming you are talking about MS SQL 2000 - as I receall MS Licensing applies to the VM so I do not think you will need to set Host Affinity

[GreatWhiteTec]

I don;t see any issues as far as SQL licensing. You SQL VM will only be running on one specific Host at a time, unless you have a SQL Cluster. Whether you are using per server or per seat licensing, I don't see any issues with letting your SQL VM stay in the HA/DRS cluster.

[rb51]

Troy: thanks for your explanation, much appreciated...

Weinstein5 & dvdmorera:  We have Server/CAL license for 2 servers running MS SQL2000 STD and Microsoft is adamantly saying that we need to run these 2 VMs in 1 host only and they want this in writing. I am trying to find docs, etc to clearly understand why they can only run in one host. Apparently there is something called "Application Server License Mobility".

As always Microsoft Licensing is so confusing....