SQL/Exchange on VMDK Questions

[bill_blair135]

I have a few questions for a new install.  Both data and logs for SQL and Exchange will reside on vmdk's.  We plan to separate the OS, data & logs onto different datastores.

1. Is the Window's NPM required on the VM to take application consistent snapshots?  Or is it handled by the VMWare tools?
2. Is it safe to set the performance policy of the datastore of the data and logs to VMWare5?  Assuming they used the default allocation size for NTFS.
3. For the snapshots synchronization I assume I would set it to VMWare.  Correct?
4. For SQL, they are planning to setup replication via a log shipping tool.  Is there anything special to take into account?
5. For SQL, if I have multiple databases sharing a datastore for data & logs is there an issue with them all taking a backup at the same time?

Thank you,

Bill

[Nick_Dyer · Accepted solution]

Hello Bill,

If you are placing your VMs on VMFS datastores then you will not need Windows NPM installed on the VMs themselves, as long as you select "vCenter" as the consistent snapshot method. This will use vCenter & VMtools to pause & synchronise the datasets before performing the snapshot. The caveat to this is you want to be conservative with the amount of VMs you are placing on the datastore; if you have 30+ VMs then all 30 will need to be paused and quieced before the snapshot can take place.

You should set the performance policy of the volume to VMware 5 if you intend to store different types of application on the same datastore. If you create a dedicated VMFS datastore JUST for SQL Logs (for example) then you can use the SQL Logs policy - the benefit here is that you're not cycling data through cache which doesn't need to be there. I would not recommend placing Logs and DB on the same datastore - create dedicated Log & DB datastores which will reduce cache burn and also optimise on block sizes at the same time.

Hope this helps!

[bill_blair135]

Thanks Nick.  It was exactly what I was looking for.

[marktheblue45]

Quote "If you are placing your VMs on VMFS datastores then you will not need Windows NPM installed on the VMs themselves, as long as you select "vCenter" as the consistent snapshot method. This will use vCenter & VMtools to pause & synchronise the datasets before performing the snapshot. The caveat to this is you want to be conservative with the amount of VMs you are placing on the datastore; if you have 30+ VMs then all 30 will need to be paused and quieced before the snapshot can take place."

Hence why I'm looking forward to VVols. One to One relationship between the VM and it's Disks/Volumes.