Use of RAID1 on the ESX host

[robwm]

Hi,

I am installing ESXi 4.0 on a server with an ASUS P5M2motherboard which has a built in RAID. I would like to have it configured as RAID1 for fault tolerance but experienced an unexpected result.

I started by configuring my server with RAID1. During the installation, I was prompted to select which disk to install ESXi on. With the RAID enabled and installing Windows, Windows would see the RAID as only one drive. ESXi is smart enough to know there are 2 drives even thought the RAID is configured.

Should I just configure RAID1, install on disk0 and figure that the RAID will replicate the data to both drives? I'm just kind of confused that the ESXi installation presented both drives instead of it thinking there was only one like you would expect.

Thanks,

Rob

[krowczynski]

If the ESXi installation is showing you 2 drivers, you RAID was not properly configured.

Is your board fully supported by vmare, or are you working in a testlab?

[robwm]

I'm not sure about the motherboard compatibility. I have an Asus P5M2 but I think P5M2/SAS may be the better choice.

So you think the RAID configuration may be wrong, I'll try it again more carefully to see if that gives me the results I was expecting.

Would this one work?

[AntonVZhbankov · Accepted solution]

This controller implements RAID on driver level, not hardware.

So you need hardware RAID controller for RAID1, that's all.

---

VMware vExpert '2009

http://blog.vadmin.ru

[bulletprooffool]

ESXi is happy tp be installed on any RAID config . . provided the config of the RAID is handled by the hardware. - e.g. on an HP server at a hardware level you'll use the ACU to configure the RAID . . then the hardware will continue to manage this. It is important to note that hardware level raid operates totally differently to Driver / OS level RAID (if you have RAID at a hardware level, the OS does not even know that is is writing / reading to multiple disks at one)

Anton is correct - you need to be managing it at a hardware level - I am not sure you motherboard can handle this without an add on controller.

[TobiasKracht]

As I can see in [HCL list|http://www.vmware.com/resources/compatibility/search.php?action=search&deviceCategory=san&productId=1&advancedORbasic=advanced&maxDisplayRows=50&key=&datePosted=-1&partnerId[]=50&rorre=0], there in no your RAID adapter. According motherboard`s spec, it uses LSI SAS1068, that is why ESX sees 2 disks.

StarWind Software R&D

[robwm]

Would you be able to recommend a cost effective RAID card or are they all pretty much the same? Do these cards present a hot-key option to configuring them like the one on my motherboard?

I see a few inexpensive options available at Newegg but I'm not sure what is known to be easy to configure and reliable.

[AntonVZhbankov]

I recommend to choose RAID controller from HCL - choose what suits you budget.

There are also cards that work even if they're not listed on HCL, but there is a line - do not try to find hardware RAID for less than 200$

---

VMware vExpert '2009

http://blog.vadmin.ru

[krowczynski]

Anton is right here, it will be better for you.

The controller from 3ware are not to expensive, check out which is supported, and then buy one!

[robwm]

It might be cheaper to buy a supported motherboard...

Does anyone know of a RAID card that is PCIx which will work with ESXi 4? I have a PCIe x16 slot which is a crap shoot whether it will work with a x8 RAID card. The motherboard manual calls it out as a video slot so I'm thinking there is a good chance a PCIe RAID card will not work in that slot. I do have an open PCIx slot though.

[DSTAVERT]

Most motherboards with built in RAID are software RAID. If this is for a production environment I would start looking for real server recommendations rather than piecing one together. There are plenty of low cost fully supported servers. If you end up looking for a PCIx card then I would look for something from LSI since they have support and there is RAID monitoring support within the VI client. Some Dell PERC cards work well in some non Dell motherboards (LSI based).

[robwm]

Mainly I was trying to set something up at home so I could learn ESXi. We use it here at work but I don't have free access to the system like I would in my own environment. I think I am going to have to give it up with this motherboard. It simply cannot support a PCIe RAID and the ESX HCL is not very extensive so I would have to take a chance at trying RAID cards until I found something that works. Unfortunately, my bank account won't support this type of experimentation.

Thanks to everyone that replied! I learned quite a bit out of attempting this process!

[Dave_Mishchenko]

Is it an ICH7R controller? How important is RAID for you? If you drop it out of RAID mode ESXi can still run on the MB and while you won't have RAID you can setup another datastore on the 2nd drive and use it for backups.




Dave

VMware Communities User Moderator

New book in town - vSphere Quick Start Guide -http://www.yellow-bricks.com/2009/08/12/new-book-in-town-vsphere-quick-start-guide/.

Do you have a system or PCI card working with VMDirectPath? Submit your specs to the Unofficial VMDirectPath HCL - http://www.vm-help.com/forum/viewforum.php?f=21.

[robwm]

At this point I would say it is more important to me to be able to run ESXi than it is to have the raid. I have two 750GB drives and not too sure how I would utilize that amount of space. I could definitely could use the space for backups and snapshots though. I may just go this route. I did already break the onboard RAID, installed ESXi and it's running fine. I haven't done anything with it so far but I would like to get a domain controller installed tonight.

[TimPhillips]

You can use software RAID in your VMs.

[robwm]

The moral to the story is this:

If you plan to build an ESXi server, then build it from the HCL to ensure it will work. I didn't originally set out to run ESXi but saw a valid use for it about a year after I built my server. It works fine without being mirrored but I will need to be diligent in keeping backups going forward. I am really happy with this new configuration and look forward to learning more about it.

Thanks to everyone who responded! You rock!