SQL Virtual Machine & vCenter (easy points)

[khughes]

I was asked in a meeting today regarding our upgrade plan to vSphere (ESX4). Our biggest hold back is an outdated SQL server that can house the vCenter DB. We're going to implement a new SQL 2008 server, which I wanted to be stand alone VM instead of how we have it now installed on the physical vCenter server.

Concerns arrose with the possibility of having a host go down that is running this SQL server and the vCenter DB and that it would bring everything to its knees. I know there are plenty of papers regarding running vCenter as a VM and if a host goes down that is running it HA is already configured on the host level to restart that VM on a different server and life is good. I said I was 99% sure that would be the same thing regarding the SQL server that vCenter relys on but wasn't 100% sure because we have never tried it nor have I tested it yet.

So easy points, are my thoughts valid, or am I missing something that the SQL database for vCenter is more important and could cause issues down the road if it goes offline?

• Kyle

[Troy_Clavell]

if vCenter goes down for any reason (including loss of the backend DB) everything except for DRS will continue to function as normal. Just have a good backup of your DB, so that if needed you can recover somewhere else.

[khughes]

So HA will power it back up and then vCenter will automatically re-attach to the SQL server (in theory) or require a bounce/services restarted. And by good backup you mean like a bulk backup with one of backup companies out there?

• Kyle

[Troy_Clavell · Accepted solution]

yes, HA will restart the VM, it doesn't care about the application inside. So, if the ESX Host, which is hosting your vCenter or VCDB goes down, it will be restarted on another host in the cluster. Yes, a manual intervention of the vCenter Server Service may be required.

A good backup meaning SQL backup.

One thing to consider, if you have admission control set on your cluster, you may consider setting the restart priority to high for vCenter and the VCDB, just so that if there are any resource contentions, they will get started first.

[msemon1]

This is a sticky issue. Because technically if the host goes down with VC running as a VM if will start on another host with HA. If the SQL server is not local on VC and is on another host the SQL server will not necessarily restart. So if ODBC connection is interrupted or services get hosed then it could cause an issue. If they are running on same server it should be fine. I am actually looking at going back to running VC as a VM. We moved ours to physical, however, with upgrade to vSphere I want to move back to running as VM. I have confidence it will run fine.

Mike

[khughes]

One thing to consider, if you have admission control set on your cluster, you may consider setting the restart priority to high for vCenter and the VCDB, just so that if there are any resource contentions, they will get started first.

This was something I already was planning on doing but a very good point Also we would be running SQL backups and those would be picked up on a FLB on a daily basis so I think we would be covered there. Thanks Troy

• Kyle