RAID Disc Trouble

[arcticeye]

Good morning,

Thank you for allowing me to write in your forum.

I recently bought an IBM M5 X3250 and I see that I will be able to install ESXi 5.5 (maximum, not 6 -If I'm wrong please let me know). Nevertheless my problem has to do with this:

I have this new server which I desire to install ESXi and just only 1 HDD by now. How can I do in the future if I wanted to installa a 2nd disk to make RAID (mirror at least) having the ESXi already working, the VM's and the virtual disks in the disk already installed?

What would you suggest me to do?

Thank you very much for your help.

Kind Regards,

Matias

[brunofernandez1]

Maybe you have to possibility to create a RAID1 only with one disk. Yes this sounds strange but with some controller this is possible...

As soon as you plug the second disk in, the sync will begin...

[arcticeye]

Hi Bruno, Thank you for yours answer.

What If I don't have any controller?

Does VMware make RAID by itself?

What if I have a FAKE RAID onboard? (i think this is not an option, but I mention it anyway).

Any other suggestions?

[brunofernandez1]

without cotroller it will not be possible to create a raid with two disks...

as I know, doesn't even support software raids....

[arcticeye]

I have this RAID controller:

RAID 0, 1, and 10 with the H1110

ON this IBM server:

XSERIES 3250 M5 4C E3-12340 V3

Partnumber 5458ECU

Would this be useful to do what you have suggested?

Thank you very much,

Kind Regards,

Matias

[cykVM]

Hi,

it's better to use a more advanced controller which should have a battery backup. As per IBM's redbook http://www.redbooks.ibm.com/technotes/tips0831.pdf

the H1110 is compatible to VMWare ESXi up to version 4.1 only. So this will have no driver for 5.x and will be pretty useless.

cykVM

[arcticeye]

Thank you for your answer!

There is something i don't understand.

You said only Vmware Esxi 4 would be capable of manage Raid, are you talking about a Vmware capability (software) of managing RAID?

Because I assume that hardware raid is independent of the SO installed (the BIOS controls it).

So...The H1110 is a hardware raid then it would have to work without any software compatibility..am I wrong?

Thank you.

Kind Regads,

Matias

[brunofernandez1]

what cykVM means is, that this RAID Cotntroller is only supported up to 4.1. normally hardware that is not supported, there is no driver for it.

so the esxi will probabelly not recognize the raid controller

you can check your hardware compatibility here

VMware Compatibility Guide: System Search

[cykVM]

No, I meant that IBM provided drivers for the H1110 only up to VMWare 4.x. The H1110 is not in VMWare's HCL at all (see/search: VMware Compatibility Guide)

With VMWare you should use a RAID controller with battery backed up cache (aka. BBU) which is only provided by IBM's Serveraid Mxxx adapters. VMWare does not do any caching and relies on the controller for that. Without caching it will be VERY slow.

Without a VMWare driver for the H1110 you won't even see any RAID volume or be able to access it in any way. You will only see the independent/separate disks at maximum.

[arcticeye]

But... Can't vmware be independent of the hardware raid? I mean, can't I configure the raid in the bios so that the Bios does the writing in the disks transpearently ??, and then vmware software will be totally independent of this, working normally as if it had 1 disk??

[cykVM]

Yes and no The OS (in this case VMWare) does need a driver for the controller to see anything (e.g. a RAID volume) configured in the controller's firmware. Without a VMWare driver you'll only the the PCI device but won't be able to access it.