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  1. #1

    mdadm assistance - RAID5 data not visible

    Initially I'd like to thank everyone on these forums for all the helpful posts... this is my first direct query and I am not very knowledgeable with regard to Linux at this point.

    After a 10 second power outage last night my Ubuntu 9.10 sever rebooted and the contents of my /dev/md0 RAID5 array were not visible. Prior to the power outage everything was working perfectly. The raid is (well perhaps 'WAS' haha) comprised of 5 1TB SATA drives.

    Attempting to discover what was happening, I have accumulated some information as follows:

    If I try to copy any data with a slash in it in this section it will not allow me to post as it thinks I am trying to post a URL prior to my 15th post... I have data that I have collected from commands and files that I can provide - can someone tell me HOW to put that information here without the system blocking it?

    If there is any other information that I can provide that would be helpful to anyone who has any suggestions, don't hesitate to ask.

    Obviously, I don't want to lose 3.8TB of data so I have not experimented with other commands like assemble or create (some posts refer to create option for mdadm rebuilding an array). If the level of loss were not so potentially high I would be willing to experiment.

    Thanks for any help or advice anyone can offer!


  2. #2
    Hey Nate,

    I just had a similar issue last night with my 4 disk, 1tb RAID 5. I was having the problem when I tried to mount it, it would say missing super block. What sort of errors are you getting when you mount it? Do you remember the order in which the drives were assembled in? If you don't, I think you can check for example like this:
     mdadm --examine /dev/sda1
    replace sda1 with any device that was/is in the array. After you get the device order, you could try to re assemble the raid like so:
     mdadm --assemble /dev/md0 /dev/sdb1 /dev/sda1 /dev/sdc1 /dev/sdd1
    That's the order that my disks are in.

    Hope this helps!

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