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I have a configuration of 4 HDD's as RAID1 2 pairs of 2 HDD's.

The first RAID1 pair is for the system, so I just made an 40GB space for swap, and the rest of it for the root. The second pair of RAID1 array is for logical use. So, in final I have:

First pair:

1 Disk:

  • 40GB swap
  • 960GB / ext4 raid

2 Disk:

  • 40GB swap
  • 960GB / ext4 raid

Second pair:

3 Disk:

  • 1.0 TB etx4 raid

4 Disk:

  • 1.0 TB etx4 raid

After the system installed, at boot up I see a strange error for about 5-6 seconds:

error: no such device: c3b8763c-4623-4fe1-9096-3aadef5cc116
Press any key to continue...

What I did wrong?

The output of ls -l /dev/disk/by-uuid is:

total 0
lrwxrwxrwx 1 root root 9 2012-04-24 15:38 c3b8763c-4623-4fe1-9096-3aadef5cc116 -> ../../md0
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2 Answers 2

up vote 2 down vote accepted

Your init ramdisk does not have raid driver, you need to feed it into initrd, and that initrd should be reachable without accessing drives that require drive modules.

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Can you be more specific? I'm not an server professional, so if you could give me a detailed answer on how I can do that, I'll be very thankful to you :) –  Denees Apr 24 '12 at 13:04
    
You need to create /boot partition which you seemingly deleted when installing. That would be the place where Ubuntu installer will save all the relevant magic to have /[root] on RAID or LVM encrypted volume. If you cannot afford repartitioning make a bootable USB stick, if you are to repartition - use LVM because it allows resizing partitions on-the-fly. –  ZaB Apr 24 '12 at 13:32
    
Ok, I'll try to reinstall it in corect way, who knows, maybe I missed something, or maybe I deleted something, thanks. I'll come up with an answer after that. –  Denees Apr 24 '12 at 13:39
    
Ok, I've waited the rebuild and that didn't gave me the success result. So I've decided to reinstall it, and it is ok now, thanks for the help. –  Denees Apr 25 '12 at 12:47
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"c3b8763c-4623-4fe1-9096-3aadef5cc116" is a UUID that uniquely identifies a disk in this case. The mapping is available for you to see with e.g.

ls -l /dev/disk/by-uuid

Apparently, your system tries to boot from the disk with the UUID "c3b8763c-4623-4fe1-9096-3aadef5cc116", which isn't found. If the link exists in /dev/disk/by-uuid, make sure it points to the correct disk. If it does not exist, you could simply create it, or even better (much better, perhaps) fix the UUID reference in the boot loader to actually look for the UUID corresponding to the correct disk.

Even if you can't boot the OS, you should at least get the option to start in superuser mode directly from GRUB (or which boot loader you now use) and fix this from the command line.

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The system starts normally. I've edited the first post with an output of ls -l. –  Denees Apr 24 '12 at 12:53
    
@DenisHoss: Great, that output shows that it tries to access the raid array /dev/md0, which for some reason isn't ready. With this information you can now continue on the path of ZaB's answer. –  Daniel Andersson Apr 24 '12 at 13:07
    
Thanks, I'll try once he will answer :) –  Denees Apr 24 '12 at 13:31
    
Ok, I've waited the rebuild and that didn't gave me the success result. So I've decided to reinstall it, and it is ok now, thanks for the help. –  Denees Apr 25 '12 at 12:46
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