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I have a Dell 2950 with 6 disks, I'd like 2 RAID 5 arrays 3 disks in each array. The RAID manager only allows me to create 1 array, after the array is created I can't create another. Why would this be?

PS I'm going to install Exchange 2010 on this box, any suggestions on disk setup are welcome.

Thanks S

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up vote 2 down vote accepted

Usually most RAID controllers allow multiple arrays, that's weird.

For MS Exchange, it is recommendable to stay away from parity RAID (RAID-5, RAID-6) because of the poor write performance. Prefer a RAID-10 setup, or you're on for a painful experience unless you have only a handful of users.

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I was about to comment about this aswell. Poor, poor raid controller if it has to maintain dual raid 5 parity. I bet it doesnt have the cache or processing power to do it fast enough. +1 for RAID10 (allthough RAID1 might be enough for this setup). – pauska Feb 16 '10 at 13:48
RAID 10 it is, just read up on it, perfect for my needs. Thanks – Steven Feb 16 '10 at 14:28
@Steven: This didn't answer your question about configuring multiple arrays. Did you get that figured out? – joeqwerty Feb 17 '10 at 2:09

For MSExchange I'd setup the server as follows:

  1. Install the OS on two drives in a Raid-1
  2. Install OMSA
  3. add four more disks
  4. Go into OMSA and create two raid-1 VDs
  5. In OMSA create a raid-0 VD on top of the two new raid1 VDs
  6. Install the exchange datastores into the newly created VDs

The PERC5i/6i controllers support multiple VDs, and everything should work, unless you don't have a controller, or something is seriously wrong with it. An old VD config that already exists might be another cause for the issue

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I am pretty sure you can do this. I haven't done in it in a while, but I think you need to create two different "Virtual Disks (VDs)", and then you create the RAID you want on each of those virtual disks specifying the physical disks (PDs) you want to use. I remember it not being that intuitive. If you have medium or enterprise support with Dell, you will probably get through to them pretty quick and they will walk you through it.

For Exchange disk configuration you might find the answer to this previous of question of mine helpful: Exchange 2003 Raid Configuration for a 15 Disk Array

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If I"m not mistaken, the RAID controller requires a split backplane in order to create two arrays. If it doesn't have a split backplane then it isn't possible. Your best bet is to call or email Dell support and check with them.

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Wow, that is really strange. I just bought several new 2950s that have:

2x72GB Raid 1

3x300GB (+1 hot swap) Raid 5

I'd get on the horn w/your AM at dell or tech support. If you are still having issues let me know and we can chat offline.

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