[I am completely new to running "bare metal" virtualized hardware, so please lead me to TFM, so I can R it.]

What I was hoping to do, is to have some kind of bare metal virtualized server setup, but where the hypervisor was taking care of running a software RAID5.

I was hoping to use all 6 of my motherboard SATA ports to 2GB disks for the RAID, thus getting a 10 TB RAID5 volume. The hope was that I then could carve this device into slices which I dished out to the different VM instances.

There is obviously a bootstrap problem here since there are no more disk ports for the hypervisor to have its own, but I was thinking that the initial hypervisor boot could be done using a bootable, read-only USB stick? Then the hypervisor could possibly use a partition of the RAID5 volume for its own OS after that initial boot?

Is anything like this possible, and how many ways to do it are there? Any good articles, blogs, whatevers to get me crackin'?

  • 1
    Sorry. You lost me at "bare metal virtualized ... thingy". May 22 '11 at 12:45
  • @Holocryptic: I've edited the post now, hopefully so that you should be able to parse it.
    – stolsvik
    May 22 '11 at 14:15

"Bare metal" is just a marketing term and thus somewhat blurry. Of course, a hypervisor is always an operating system, even if reduced in functionality compared to a full-blown one and usually somehow "embedded" into the system itself (e.g. using a USB DOM). ESXi and XenServer fall into this category, Microsoft's Hyper-V, Linux KVM or Oracle VM run virtualization in Kernel mode and might fit a broader definition of "bare metal".

Depending on the featureset of the solution you pick, you might get or not get "software RAID 5". ESXi does not support it, Microsoft Windows (Hyper-V) does, most Linux distributions (KVM) or Solaris (VM) do support stripesets with parity (equivalents to RAID levels 5 and 6) one way or the other. I am not sure about XenServer - in the early days (about 2-3 years ago) it did not support software RAID, this might have changed in the meantime, but I have not checked since then.

  • Thanks a bunch - you obviously know the stuff! Yes, I know that the term "bare metal" is blurry, and that the hypervisor is typically an actual OS with reduced feature set. But that was actually why I expected it to be able to run a SW RAID.
    – stolsvik
    May 22 '11 at 12:37

Download the Ubuntu install iso, burn it to a CD, and boot from it. The ubuntu installer will get the RAID set up for you.

I'd recommend at least RAID6, though. With disks as large as you're using, rebuilds are going to take a long time. Using RAID6 will protect you from a dual-disk failure.

  • Do you mean that Ubuntu will then be the bare-metal hypervisor? And don't such standard installs require that you use RAID 1 for the boot partitition?
    – stolsvik
    May 22 '11 at 12:42

Not the answer you're looking for? Browse other questions tagged or ask your own question.