Virtual Machine on SAN - RAID 1 or RAID 5?

[haripadmam]

Hi folks,

I know it is the best practice to keep the ESX OS disk on RAID 1. But what about Virtual Machine OS on SAN? Can we keep it on RAID 5 SAN DISK? Please let me know which is recommended as per VMware Best Practices...

Thanks in advance...

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Regards,

Hari.

[a_p_]

The RAID level for the disk on which you install ESX is not really important (except for disk failures/protection) since there is not much disk activity on it. You can even run ESXi from an SD card without any performance issues (except for a slightly slower boot). For the SAN LUNs/datastores it may depend on the VMs you are running, however with a current storage system and enough disks/spindles in a RAID set, a RAID5 should be fine for most use cases.

André

[ewilts]

with a current storage system and enough disks/spindles in a RAID set, a RAID5 should be fine for most use cases.

As a storage and backup/restore guy up until last week, "enough" spindles in a RAID5 leans towards FEWER rather than MORE.  I have seen way too many double-disk failures in a RAID5 set in my career.  Every time I hear another case of somebody creating a single RAID5 set out of a 14-bay of disks I just cringe and start the count-down until I'm asked to figure out how to help them get their data back.  Keep RAID5 sets small and keep a hot-spare configured at all times.