vmblogger
Contributor
Contributor

RAID setup with Hypervisor

I want to try ESX4i hypervisor and use it to validate a need for our company.  We have a SuperMicro H8DMU server with 4 SAS drive bays and a SAS Raid card.   I've inserted 4 SAS 15k drives.   Can I setup RAID3 for the 4 drives and then install ESX4i?   My thought is to setup the drives as a single volume partitioned to allow minimum required VMFS partitions and maximize the remaining space for VM files.

Or, is there a better setup?

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a_p_
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Leadership

The RAID configuration you setup on the controller is completely transparent to the OS (ESXi), so you could actually configure any RAID level as long as the RAID controller is supported by VMware.

... allow minimum required VMFS partitions and maximize the remaining space for VM files.

The VM files are located on the VMFS partition. What you may want to do is to create a logical volume for the Hypervisor (~10GB is enough) and use the remaining disk space for the VMFS volume(s). The maximum size for ESXi 4.x is 2 TB minus 512 Bytes.

André

AndreTheGiant
Immortal
Immortal

In order to have good performance be sure to use a good RAID controller (better are with RAM cache and battery).

As written you must keep your logical disks smaller than 2 TB - 512B, otherwise the hypervisor will not see the right size.

Andre

Andre | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro
a_p_
Leadership
Leadership

I agree with AndreTheGiant, without write cache - which allows the controller to operate in write-back mode (opposed to write-through without cache) - the disk performance might be as low as ~5-10 MB/sec even with the 15k SAS disks. The Hypervisor does not do any OS based write caching - for data integrity reasons - and fully relies on the capabilities of the controller. With write cache (aka. BBU, BBWC or FBWC) the disk performance usually is ~80-100 MB/sec (or better).

André

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vmblogger
Contributor
Contributor

thanks for all the advice

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