Multiple Virtual Disks vs 1 Virtual Disk

[Joshua Martin]

Thanks for stopping by and reading my post. I hope someone could clarify a question I have about setting up Virtual Disks.

Info:
8x 6TB 15k SAS drives
Dell PowerEdge R440 as a VMHost
Multiple VMs ranging from a large file server, print server, app server, etc (around 8 or so total)
RAID 1+0

My question is, should I make 1 large 24TB virtual disk and put all the VHDs on it or should I split them and make 4x 6TB virtual disks with a couple of VHDs on each virtual disk?

I'd prefer to make 1 large 24TB virtual disk to store them all, but I wasn't sure what the performance impact would be.

Thanks!

 

[justin.m.beauvais]

For redundancy splitting them would make more sense. That way if you have a drive crash it only affects some of your VMs. The remainder will stay online while you hot swap in your replacement drive, which hopefully has a fairly current backup of the drive that failed.

A large drive wouldn't necessarily yield better performance if your VMs all need to access the drive at the same time, and if there is a file system error on the server you bring everything down as a result. Now, you mitigate that with your RAID setup, but it remains a possibility.

Generally you run VMs to compartmentalize things, but putting all the VHDs on one drive is counter to that idea.

Hope that helps.