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My RAID drive was working well with Ubuntu 10.10, but after doing an upgrade I am no longer able to mount my RAID drive. I think it is due to a invalid RAID description similar to this problem:

Thing is, I never had mdadm installed as far as I can tell. How do I change it back so that my system recognizes the RAID drive. The RAID drive is configured from some sort of software RAID on my motherboard I think.

blkid gives the output:

/dev/ramzswap0: TYPE="swap" 
/dev/sda: TYPE="promise_fasttrack_raid_member" 
/dev/sdb1: UUID="a-UUID-number" TYPE="ext4" 
/dev/sdb5: UUID="another-UUID-number" TYPE="swap" 
/dev/sdc1: UUID="another-UUID-number" TYPE="ntfs" 
/dev/sdd: TYPE="promise_fasttrack_raid_member"

Any help is much a appriciated.

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if it's done by your mobo it isn't software raid, it's hardware raid. if it didn't work after upgrade and you did the initial install with raid it's software. you may not have mdadm installed even though you have software raid. apt-get install it and go through the troubleshooting steps. – RobotHumans Apr 28 '11 at 12:18
It is hardware RAID so I don't think mdadm will helt then. Right now all I can think of is just waiting for a kernel update. Any suggestions? – Paul Apr 28 '11 at 13:04
I think it can be referred to as fakeRAID: – Paul Apr 28 '11 at 13:07
Indeed, it is fakeraid, not hardware raid. – psusi Apr 28 '11 at 13:25
up vote 0 down vote accepted

This doesn't really fit the question/answer model of stackexchange, so you may want to create a thread over at You definitely have a fakeraid and should see You also might want to read the man page for dmraid and see if the raid device shows up in /dev/mapper/. If it does not, you will need to try running sudo dmraid -ay and see why it refuses to activate the array. You might add -vvvv -dddd to get extremely verbose debugging output.

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Thanks psusi! In /dev/mapper I have: control and nothing else. Doing dmraid -ay I get: RAID set "pdc_gjgbcdghd" was not activated Doing the debugging output: NOTICE: added /dev/sdd to RAID set "pdc_gjgbcdghd" DEBUG: _find_set: searching pdc_gjgbcdghd DEBUG: _find_set: found pdc_gjgbcdghd NOTICE: added /dev/sda to RAID set "pdc_gjgbcdghd" DEBUG: checking pdc device "/dev/sdd" DEBUG: checking pdc device "/dev/sda" DEBUG: set status of set "pdc_gjgbcdghd" to 16 RAID set "pdc_gjgbcdghd" was not activated – Paul Apr 28 '11 at 13:45
@Paul please file a bug report at Please title it something like "promise raid not recognized in Natty". Also run sudo dmraid -rD. This will put some files in a directory named dmraid.pdc. Please tar this directory ( tar czf dmraid.pdc.tgz dmraid.pdc ) and attach the tar file to the bug report. – psusi Apr 28 '11 at 15:16
Thanks psusi. I have added it here: How long could this take before I can access my files do you think? – Paul Apr 28 '11 at 16:00

I wrote this up a while back, but it may be pertinent to your situation:

Read through the steps there, but note that you're using FakeRaid instead of Software Raid (mdadm)

Here is an explanation of the general concept plus the appropriate substitutions you'll need to make for FakeRAID (untested) Basically, you'll do the following:

  1. Boot your system using a live disk, it must be the same or newer than your installed distro
  2. Once booted into the live environment, install the software necessary to enable FakeRAID support

    $sudo apt-get install mdadm dmraid

  3. Now load the modules required for your FakeRAID chip and your version of raid

    sudo modprobe dm-mod raid0 raid1 raid10 raid5

  4. Assemble the array sudo dmraid -ay

  5. Mount your raid partitions (root, boot, home)

  6. Bind the live environment's resources to the mounted partition, thus creating a type of hybrid environment between the live system and your installation

  7. Enter the newly created environment and perform simple grub repair

    sudo apt-get remove grub-pc --purge sudo apt-get install grub-pc

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