# Lost RAID partitions

## passive

Hi all,

A few weeks ago I began bringing my server up-to-date. After all the packages were upgraded, it worked fine. Last night, the machine suffered some kind of attack or other performance issue, and it needed to be rebooted. Since the reboot, I can no longer access my RAIDed (mirrored) partitions (/dev/md*). Dmesg shows some kind of construction of the arrays, and that appears to work properly, but the /dev/md* files aren't there to mount.

I found some references suggesting udev might a problem, and sure enough, it wasn't starting because the version I had was for baselayout-2. So I upgraded to baselayout-2, and now udev is complaining that it only work on kernels 2.6.25 and above. I'm running .20 right now, and I did build a .28 kernel, but because my /boot partition is part of the RAID array, I really have no idea how to boot it.

Any ideas for what I can do? Any likely culprits for this failure?

Thanks!

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## NeddySeagoon

passive,

Read 

```
man mknod
```

 and make the /dev nodes by hand.

The device major number for /dev/md is 9, minor numbers run from 0 to 255

```
mknod /dev/md0 b 9 0
```

creates /dev/md0 for you.

You will need to change the permissions, owner and group afterwards so they match

```
brw-rw---- 1 root disk    9,   0 Jul  3 11:59 md0
```

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## passive

Yippee! It seems to be working! Thanks so much!

Man, that was pretty hairy there for a moment. Will the /dev/md* entries persist after a reboot?

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## passive

My assumption is that the /dev/md* entries aren't being created automatically because of the lack of udev, so I tried to boot the newer kernel. Unfortunately, that doesn't seem to have worked, and it's not falling back to the old one, so I'm out of access to it at the moment (it's on the other side of the continent). Hopefully my host can help.  :Smile: 

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## NeddySeagoon

passive,

I suspect you need a matching udev/kernel set.

By default /dev is in shmfs (in RAM) so the nodes will not be persistent

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