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We are buying a dual hex core ibm x3650 with 64 GB RAM and 7x300 GB HDD. This server is hosting two virtual servers, web server and database server. I am using Double take high availability to replicate the database into a different physical machine. Veeam is used to backup the virtual servers every night.

I was wondering which RAID configuration is best for the environment.

RAID should meet the following requirements:

  1. At the time of failure or rebuilding the array, less chance of data corruption.
    • Otherwise corrupted data will be replicated to another system
  2. As these are production system, performance needs to be high and downtime should be minimal

Any Suggestions?

ewwhite
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Ankit
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2 Answers2

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Neither. If virtual machine performance is paramount, you may want to consider RAID 1+0 with a hot-spare instead of one of the parity RAID variants.

VM activity tends to be mixed random read/write activity. RAID 6 is poor at the random write game. RAID 5 should probably only be considered if you're space-constrained.

RAID 10
Good when: You want speed and redundancy
Bad when: You can't afford to lose half your disk space

RAID 5
Good when: You want a balance of redundancy and disk space or have a large sequential write workload.
Bad when: You have a high random write workload or large drives.

RAID 6
Good when: You want a balance of redundancy and disk space or have a large sequential write workload.
Bad when: You have a high random write workload.

Some of the design considerations and explanations are covered in this post: What are the different widely used RAID levels and when should I consider them?

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ewwhite
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    Good idea; RAID-10, plus a hot spare. On the vSphere side, thin provision all of the servers, except for the DB server. Depending on the load and write activity, you may need to thick provision it's data drive(s). We use reverse incremental under Veeam. – jftuga May 14 '12 at 15:14
  • @jftuga I have to thick provision DB for sure. I can thin provision the application server because it is more stable. – Ankit May 14 '12 at 15:31
  • @ewwhite Thanks for the quick response. I am gonna go with RAID 10 because i don't have a storage space issue at the moment. My current storage of both the servers is 200 GB. With RAID 10 I will have 900 GB with 6 Disks + 1 Hot Spare. – Ankit May 14 '12 at 15:37
  • @jftuga I meant Application server Storage is static not increasing daily – Ankit May 14 '12 at 17:02
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I'd go with RAID6.

The performance hit is not large enough to justify raid5, but there is a large enough benefit when one of the drives fail. Since all the drives are from the same series, and with the added load of a raid rebuild, there's a chance another drive will fail too.

A simmilar question was asker before here, and goes with raid6.

If it's possible, consider raid1+0 (+spare); you'll need more drives, but achieve a greater speed.

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mulaz
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