topic Re: P2000 vDisk Configuration in MSA Storage

P2000 vDisk Configuration

Network Manager — Thu, 03 Jan 2013 16:31:56 GMT

We have a G3 P2000 FC (dual controller) with 12 300gb 15k SAS drives for use in a new vSphere enviroment. Small user base < 50. There will be approx 8 to 10 servers ranging from 50 to 100 gb in size with multiple volumes (ie OS c: , Data Volume d: , etc) including an Exchange server and a database server. We are trying to plan the vDisk configuration. MSA documentation says to balance the vDisks with the controllers. However, the amount of drives available are considerable reduced if we use 2 RAID10 vdisks. Possible options were:

ControllerA - 6 disk RAID10 (900gb)
ControllerB - 4 disk RAID5 (900gb)
2 Spares

ControllerA - 5 disk RAID5 (1200gb)
ControllerB - 5 disk RAID5 (1200gb)
2 spares

Is it necessary to split the vDisks?

What would be a good size for the volumes(LUNs) to hold datastores in this scenerio?

Is there a considerable difference in using RAID5 vs RAID10?

Many thanks in advance for any advise.

Re: P2000 vDisk Configuration

Torsten. — Thu, 03 Jan 2013 16:49:14 GMT

each vdisk is owned by a controller, so if you have 2 vdisks, each controller can be an owner. Read the wiki about the RAID types, RAID5(0) provides more space than a RAID1(0). You don't need 2 spares, a single global spare should be enough.

Re: P2000 vDisk Configuration

Network Manager — Thu, 03 Jan 2013 20:45:30 GMT

Thanks for the reply. This is our first SAN, so wanted to be sure it was set up correctly the first time. I'm still trying to wrap my head around the VMware datastore to LUN relationship. The amount of LUNs may be somewhat limited when the drives are split. Research suggests LUNs in the range of 500 - 7000GB. We may only have approx 900gb per array, depending on RAID selection.

Is it correct that there will be a datastore for each LUN?

What would be a good size for a LUN/Datastore?

Currently, all our phsical servers are RAID5 and work well.

Should we expect the virtual machines to perform the same?

Thanks again for any assistance, it is greatly appreciated.