New ESX server - RAID? Noob


We are installing our ESX server this weekend and I wanted to know what I should do about our RAID config. Currently we have a Compaq DL 380 G5 with 8x 146GB 10k drives.

After reading a lot of people have their ESX OS on two mirrored drives... but I would lose 2x 146GB drives solely for the OS.

We have the free VMware server product in production and we're going to use the converter to convert and push the VMs to the ESX server. For the VMs some people say RAID 5, others RAID 10... arghhhh

So my question.... with the hardware I have how should I set up my arrays and what stripe size is optimal for high I/O?

Thanks so much in advance... much appreciated.

Message was edited by: oreeh

Removed the smiley from the subject

Oliver Reeh

VMware Communities User Moderator

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What a question...

Most ppeople Mirror RAID the Disks where the OS resides as this give the best resilience / redundancy, and also using smaller disks.

In your case, if you do want to mirror the 146GB disks, theres no reason as to why you cant put any vm's on it.

Being generous, you would only need approx 20GB for all of the neccesary/recommended ESX partitions. The rest can be formatted to store vm's. (and dont forget iso images and templates etc...)

RAID 10 or 5, I find that quite difficult to answer. Obviously 10 is better performance but cost more than 5

You'll have to weigh up whether you want the performance or the storage. I havent experienced any performance problems so far with RAID 5. Maybe others on the forum can comment on their experiences.

You could even, do both RAID configs, if you want to play around.

Good Luck


If you found this or any other answer useful please consider the use of the Helpful or correct buttons to award points ~y

That is a tricky situation. All of our servers use a RAID1 configuration but we also utilize a SAN so our local space doesn't house much if anything at all. Our SAN though is a RAID5 and we don't see any performance hits there. The only thing I could possibly semi-relate to your problem is that our R&D ESX hosts run 6 physical hdds with a straight RAID5 across them and install the ESX os onto a large local drive space. I haven't seen any performance hits on doing it this way but then again its R&D and the stress of running full production environment isn't there.

  • Kyle

-- Kyle "RParker wrote: I guess I was wrong, everything CAN be virtualized "
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Use Raid 1 for OS (read performance) and Raid 5 for Data(write performance)

for more details on Raid please visit the

here you can calculate your disk spaces and decide which raild should use.

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