Disk setup for Virtual Machines

[Smudly]

I will be setting up an ESX server in the near future and I was wondering if there was any benefit to splitting up the disks. for example

using 2 mirrored disks for the ESX software and the root drive of server 1

using 3 disks in a raid 5 arrary for the data storage for server1

using 3 disks in a raid5 array for a server2

and so on.  

I know this obviously takes more disks than a single datastore. I want to know if there is any performance benefit to separating them or if it is better to just use one large datastore for everything.

[DSTAVERT]

I would consider ESXi rather than ESX since this is the last version for ESX. The next version will be ESXi only. ESXi can be installed to USB or SD cards. Many major OEMs (HP, IBM,  Dell, Fujitsu and others) provide internal USB or SD card slots  specifically for this. The splitting the datastores wouldn't be important but that would be dependent on how large the VMs will be. There is a LUN limit of 2TB - 512 bytes.

[AndreTheGiant]

Welcome to the community.

As suggest you can use ESXi on a SD/USB memory (http://communities.vmware.com/docs/DOC-11349).

Then the datastore disks can be organized to use the best RAID level according on your requirement.

I suppose that you are talking about a host with local storage.

In this case you have to choose a really good RAID card (with at least 512 MB cache and a battery).

Andre

[a_p_]

Splitting the disks into small RAID5 sets will result in a much lower performance than combining all disks in one large RAID5 set and split this into multiple logical volumes.

I'd recommend you either install ESXi on a USB/SD device (as DSTAVERT recommended) or split your RAID set into appropriate logical volumes. I usually split the RAID set in a way, where I create a small (~10GB) logical volume for the ESXi setup and one or more larger logical volumes for the VMFS datastores. As mentioned above the current limit is 2 TB minus 512 Bytes.

André