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I have a Dell Poweredge T110 2, with a Perc H200 raid controller and running SBS2011. Recently one of the disks in the non-OS raid began to die, so we thought we'd upgrade to larger disks, so I changed over the disks, and removed and re-generated the array, this all went fine, but when it came to booting the system I noticed it had actually formatted BOTH Arrays associated with the RAID card.

This obviously irritating, but i thought that's fine I'll just restore the system image i'd be taking daily with Backupassist, however no matter what i try, EFI/BIOS etc, this poxy server refuses to detect the fully working system image, and refuses to detect ANY drivers. This is Odd as i can boot from the Zalman Virtual CD drive just fine, but it won't then detect the USB HDD where the system image is located, as if it's not connected to the system. (I have it in the back USB, but it CAN detect the filesystem on one of my other backup drives also in the rear,and the zalman in the front). The original OEM driver/OS disks for this were lost AGES ago, and when i go to "OS deployment" in system services, it just says "Cannot find efi catalogue for the drivers, so I'm not really sure how i can recover this system.

Any ideas how I can get this system image to restore on the server?

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Despite the name, the H200 RAID controller is NOT a hardware RAID controller. It tries to lie to you as much as possible, but essentially it is a really bad RAID bios to generate software RAIDs. The problem is that any OS that is NOT running the dell perc drivers (Linux?), will see the disks as a bunch of independent disks, and ignores the pseudo-raid entirely. When restoring, or writing to a pseudo-raid volume, the data is not written to the mirror... which leads to the pseudo RAID bios to panic.

As far as I'm aware, there is no way to backup the disks in such a way that you can restore them in a perc RAID volume. You would be better off disabling the perc pseudo RAID, and simply use the OS'es native software RAID capabilities. (CPU/RAM/etc... will not be affected any-more than the perc was already doing)

  • Doesn't the perc load the raid before the OS bootloader however? As i'd think this would offer some more stability than a RAID constructed by the OS? Or have i completely misunderstood how this is working? – user3407675 Feb 5 '16 at 22:47
  • Nope. There are PERC hardware RAID controllers... but the H200 is not a hardware RAID. By hardware RAID, I mean that the RAID controller has its own CPU, and its own internal BIOS that presents RAIDed volumes to the subsequent layers, rather than independent disks. The H200 uses the internal CPUs and memory to do all the RAID bits, and does NOT have an actual BIOS that presents RAID volumes to the guest OS. – TheCompWiz Feb 5 '16 at 22:48
  • Ahh i see, so I'd be better off rebuilding using the system image to a non-raid, then getting a proper Dell RAID card to put in it and rebuilding the raid and imaging onto this? And is this raid "software/firmware" why it's refusing to detect my system image properly? And will this cause an issue restoring the system image to the non raid? (was 1 TB raid 1 before, and those exact disk are still present) – user3407675 Feb 5 '16 at 22:54
  • That's debatable. If you were content with the performance of the old system, you could simply use a software RAID by the host-OS. They are pretty reliable for the most part. If you're looking for a boost in IOPS or reduce CPU used on the host, you'll definitely want to consider using a proper RAID card. (doesn't have to be a dell branded RAID controller... but you do get some nice integrations with iDRAC and such) – TheCompWiz Feb 5 '16 at 22:58
  • @TheCompWiz is correct. Their H7xx and 8xx series (Megaraid) are actual raid controls. – Aaron Feb 6 '16 at 0:58

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