Linux – Xenserver 5.5 doesn’t see RAID volume

first of all, you need to get the system back online

1. insert both old drives in the slots they were in, go into the raid utility (Ctrl+A or Ctrl+E on POST, can't remember which one)
2. the utility might recognise these old drives and bring the array back up itself. If it doesn't, you need to remove the disks, clear the controller config, insert the disks back in, and create a new raid array, VERY IMPORTANT - do not allow the controller bios to initialise the array - this will destroy all the data you have.

at this stage you should have the old config back up and running.

next you remove the faulty disk, replace it with a new disk, and assign the new disk as hotspare. this will have the array rebuilding onto the new disk (using up 36Gb out of 146) after the rebuild is complete, replace the second 36Gb disk, and rebuild again.

this should place you in a setup where you have two large drives in raid-1, using up 36Gb on both.

What you can do now is create a new logical disk (raid array) on the rest of the drives, and either mirror it or use separately. this will give you the extra space as a separate partition

I am a little confused in this description, does this 1:0:4 interprets to Controller1, Disk4. Does this integrated raid card have two controllers coming out of it ?

I think that it is still technically one controller. EDIT: @techieb0y has the right answer to this part of the question below.

Also, When I first switched on the machine, the boot partition was showing 1GB Available out of 40GB, now its showing 38GB available out of 40GB.

Is this because the Virtual Disks are still Initializing ?

Yes.

Any recommendations or suggestions ?

Wait until they are finished initializing.

Also, this server have 6 x 500GB NearLine SAS Hard drives, what would be a good raid config ?

This really depends on your needs, and I am sure there are many threads here on ServerFault that talk about the benefits and drawbacks of various RAID configurations in various scenarios. What is most important to you? Safety? Speed? Maximum volume? When I'm in doubt, I usually stick with a RAID5, cause it offers a good combination of performance and safety.

We are planning to use it for Hyper-V with quite a few (7 or 8) virtual servers, your suggestions would be helpful.

Depending on how much RAM and CPU you have, and depending on what you are doing with these systems, that might not be that many at all. I've run as many as 30 simultaneous VMs on my similarly spec'd hosts (although running VMware ESX and not Hyper-V). But those VMs have all been "light-duty" machines that aren't heavily utilized.

Also, while the virtual disks are in a initialization state, can I destroy and re-create the raid configuration ?

Yes, I've done this many times on my R710s with no ill-effects. Just make sure you do a new initialization before using them.

I would have to do it at the BIOS CTRL-M ?

Yes, as far as I know, this is the only way to do it. There might be others though, I haven't looked for any alternatives.

Hope this helps. Good luck,

--jed