We have inherited Hyper-V environment (2008 R2) with SAN storage (HP4500 hardware). Two hosts and two SAN's for redundancy. Whilst I understand virtual machines well, I guess, my knowledge of storage is very weak. I am trying to understand how our MSP engineer designed it and why. That was intro part, here is the main part.
We have 5.32TB of usable space on each SAN, and four volumes on Hyper-V host machines: Volume1, Volume2, Volume3 and recently created Exchange volume for Exchange server. On HP management console I can see according (LUN?) volumes have size of 3TB, 1.79TB, 2TB and 1.07TB. It might look over provisioned, by that is not a main question now.
My question for now is how decision was made to create these volumes and for what reason? Why not create one large volume or a lot of small volumes?
I have tried researching and after few articles, especially this one: https://technet.microsoft.com/en-us/library/ff182320(WS.10).aspx#BKMK_LUNs it makes sense. I do not want to make any assumption and posting my question in case it might be wrong, I do not want to confuse other people who is looking for a similar answer. I will try asking instead.
Dividing storage into few volumes is for performance reason and to prevent disks to be too full or overwritten?
How do I decide on which volume should I store my new VM - I should create all system VHD on one Volume and all data VHD on another?
If yes and if a lot of VMs have a single VHD file then what if one volume will have too many of VHDs and size will grow?