My office's server has failed recently after a power outage (we have no UPS).

It turned out that it will not even boot into Windows (not even safe mode). The server was running in RAID 1 consisting a pair of mirrored WD 1TB drives.

During boot, the Raid controller (comes with ASUS mobo) displayed that the array is degraded, so I thought something went wrong with one or more disks. I pressed control + i to go into the Raid Controller configurations, and see that the controller recognized that the array is degraded. It suggested to label it as REBUILD, and says that the rebuild process will happen within the OS.

Upon exiting, the machine attempted to boot into Windows and I am assuming that is to rebuild the raid 1 array. However as I pointed out earlier, Windows will not boot.

I have tried inserting the Windows installation disc and tried the recovery options. It was able to recognize the Windows installation, however it won't even run memtest.

  • How do I rebuild the array in this situation?
  • What may have caused Windows to be unbootable? (BIOS recognizes both drives)

Power outage happens all the time, I have had my home PC shut down due to sudden power loss a few dozen times and I have had no problems with it. It seems like my office's server hardisks are in seriously bad shapes due to just one power outage, which I can only say bad luck. However, am I missing something here? Is it only a software configuration issue? Most Raid 1 settings will revert to the working physical drive if one goes out, and will be rebuilt automatically. Does my situation indicate that both drives are damaged?

I hope someone can help me find the root cause and a potential solution to this, your help and time are much appreciated, thank you.

  • What model motherboard & is the RAID controller listed separately?
    – Andrew
    Jan 16 '12 at 6:21

Raid is a HARDWARE solution to redundancy and does not protect from software errors. It is very likely (99%) that the raid card on the MOBO is a Fake-RAID. What i mean by this is that the raid is implemented in SOFTWARE. While there are merits for and against software raid i wont go into them here. What i think has happened here is that during the power problems the system was in the middle of a write and ended up with a semi corrupt drive. because the writes are replicated on both drives an error on one drive is an error on the other.

It is likely if you run a CHKDSK it will resolve the problem. this may need to be done from another computer. if you care about the data i would clone a drive to another spare HDD and not touch it.

However many FAKE-RAID and even RAID controllers mess around with the first hundred bytes or so and the drives can look un-formated to other systems so its likely you will have to use a windows install CD to get into recovery mode and run CHKDSK from there

  • 3
    I don't think it's wise to make blanket negative statements about software RAID. Granted, there have been some very bad implementations over the years, but some of the most compelling work in storage over the past few years have been in the realm of software volume management and RAID, namely ZFS and btrfs.
    – EEAA
    Jan 16 '12 at 5:58
  • 2
    Not all onboard RAID is FakeRAID; e.g. some SuperMicro boards have Adaptec controllers onboard.
    – Andrew
    Jan 16 '12 at 6:19
  • @ErikA sorry i didn't mean to make the impression that all software raid is bad, edited post.
    – Silverfire
    Jan 16 '12 at 6:32
  • @Erika I'm willing to blanket state there is no business justification for using software raid. There was a time when a raid controller expense was more than the computer. Now it's simply a question of choosing a motherboard or big box server vendor. The OP is a perfect example of why not to trust software raid.
    – Jim B
    Jan 16 '12 at 15:27
  • @JimB - I'll be the first one in line to not recommend Windows software RAID, however...there are many advantages to using the very well-tested linux software RAID over a hardware solution. Additionally, with ZFS (and soon btrfs), you can obtain (for free) performance, flexibility, and resiliency that is unparalleled except in high-end enterprise SAN solutions.
    – EEAA
    Jan 16 '12 at 15:42

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