RAID 1 with esxi 5.1

[Divide_Conquor]

Just built a new system and installed esxi 5.1.

Before I installed esxi, I configured a mirrored raid (raid 1) between two disks. How can I confirm that my disks are truly mirrored? I have the option to enable one of the disks as an additional datastore in vsphere, so I don't feel very confortable that mirroring is working.

Thanks!

[mcowger]

If you can see both drives, then they aren't being mirrored.

Do you have a builtin-RAID controller, like from Intel?  If so, they wont work for RAID in ESXi because they are so-called 'fakeRAID', where its all really done in drivers, not hardware.

[Divide_Conquor]

Bummer. I do have a build in controller. You hit the nail on the head. Looks like I'll be spending some more money in the near future.

Thanks for the quick reply Matt!

[markpattersones]

Thats strange. I would have thought if you had configured it for RAID in the BIOS you would not even see the drive in ESXi let alone be able to use it. If you can see it and use it I would assume the mirroring is still working. Can you test it by filling up some space and then rebooting into the BIOS.

[Josh26]

markpattersonesq wrote:

Thats strange. I would have thought if you had configured it for RAID in the BIOS you would not even see the drive in ESXi let alone be able to use it. If you can see it and use it I would assume the mirroring is still working. Can you test it by filling up some space and then rebooting into the BIOS.

The situation he describes is completely normal for two disks that are presented - only through the use of a software driver - as one RAID mirror.

This is a common issue due to non-hardware based RAID cards, and I believe based on what he is seeing, the situation is already demonstrated.

[markpattersones]

I thought onboard RAID just flat out didn't work with ESXi but haven't tried it. Use cases are limited but I would be interested in knowing more about this.

So I build an ESXi box on a motherboard with onboard RAID. I install ESXi to USB as normal

Then I configure a RAID array will ESXi always see the array as one disk as in the original post or does this only work with some? Will it work properly?

I assumed no onboard RAID controllers would have made it onto the compatibility list whether or not it works (ie. I can buy $10 NICs that aren't on the HCL and they work).

As unsupported hardware RAID has so many problems I thought onboard RAID would never work if not on the HCL. Especially as onboard RAID seems to require more OS awareness than hardware RAID.

How does it do rebuilds etc. for example with Intel onboard RAID it uses a Windows driver to do rebuilds.