MaxVM
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Contributor

Dell 2950: raid settings

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I just got a Dell 2950 and I'm setting up the raid arrays:

2x146GB (Raid 1) for VI OS

3x146GB (Raid 5) for VMFS1

3x146GB (Raid 5) for VMFS2

What is the suggested stripe size for VMFS on Raid 5? Is it a good thing to enable the Read-Ahead on all arrays? Thanks.

Max

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bolsen
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Considering what you are going to be running, I would agree with the 3 array strategy. Start with 64K stipe size and adjust if needed. Enable both write and read cache.

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Cloneranger
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I would only have read-ahead and write-back enabled if the your array controller has backup batteries, most modern controllers should have,

64k stripe size would be the one to go for, that said its the alignment with the partition table thats key to the performance not a specific stripe size,

As a matter of interest why do you want to create 2x 3 drive RAID 5 arrays? is there a reason for the separation? (ie Database files on one and Log files on another etc)

It would be more efficient to create a single array of 6 drives and create 2 logical drives,

MaxVM
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Contributor

I'm going to run Exchange 2007, Win 2k3 File Server/DC, Sharepoint/SQL server for a small network of 70 users. It was suggested to me on this forum that creating 2 separate arrays would be better for performace. So I was thinking of putting Exchange on one Raid 5 and the rest on the other one. Right now I'm just playing around with it so I'm still open for suggestions.

Max

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bolsen
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Considering what you are going to be running, I would agree with the 3 array strategy. Start with 64K stipe size and adjust if needed. Enable both write and read cache.

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Cloneranger
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Yes exchange server should separated from its datastores, and SQL Server database files should be separated from their logs,

Thing is RAID 5 on three disks is almost as slow as RAID gets,

It would be great if you could scare up just 2 more disks, 2x 4 disk RAID 0+1 arrays would blow the two other arrays away,