Help with storage configuration for vSphere 4

[Virtugirl]

Hi All,

I am currently designing the datstores for our new vSphere installation. The VM's will be Windows Servers with a default configuration of a logical C and D drive. Some servers will have additonal logical drives. Some of the team think that it will be better to place the virtual disks for the C drive in one VMFS volume whilst placing the D Drive Virtual disk in another.

Are there any performance issues or benefits with this configuration or is it better to store all of the virtual disks associated with one vm in the same datastore ?

If we do split the vmdks into different datstores could this affect pagaing if the pagefile is stored on the logical D drive ?

The storage is an HP EVA 4400 with SAN Disks (which is currently being proposed to store the C Drive virtual disks) and an MSA 1500 (SATA) (currently proposed to store the virtual disks for the D drive).

Thanks For your help

[mike_laspina]

Hi,

There are some important items to think about when distributing the VMs vmdks. The most important element is where the VM definition will reside. This is important because the VMFS metadata is updated based on where the definition exists which is usually with the first vmdk, thus you can quickly overload a VMFS store with SCSI reservations if they are all stored on one VMFS LUN. I do distribute my VM vmdks on different VMFS volumes but still keep the total VM definition load withing the best practices limits. There are benefits using this practice like you can have raid10 VMFS stores for IO intensive applications and raid6 for less demanding loads.

Regards,

Mike

vExpert 2009

[Virtugirl]

Hi Mike,

Thanks for the reply. I believe we will be storing the VM definition files with the first disk. Is there a document that covers the best practice limitations for scsi reservations on the datastore ? Or do you know them ?

Im also a little concerned that doing it this way might introduce issues with our VCB backups.

Thanks Again.

[mike_laspina · Accepted solution]

Yes there are, check this post that Andre pulled together.

http://communities.vmware.com/docs/DOC-10990

vExpert 2009