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I'm trying to access data on a hard drive using a rescue system. I've mounted the root partition as so:

mount /dev/md1 /mnt

If I do

cat /mnt/etc/fstab

I see

/dev/vg00/var  /var     xfs

So I tried:

mount /dev/vg00/usr /mnt/usr/

But I get the error message:

mount: special device /dev/vg00/usr does not exist

Why does it say that the device doesn't exist if it exists?

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Well, thanks for that editing, my english... – Jorge Bellido Apr 27 '12 at 9:54
I love you guys, it works!! – Jorge Bellido Apr 27 '12 at 10:26
up vote 3 down vote accepted

Try this:

vgchange -a y

And after that try mounting again.

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Ok, thanks, i'll try. – Jorge Bellido Apr 27 '12 at 9:42
I only can mark this answer like correct. Can't vote you up because people vote -1 my questions :( sorry and thanks!!!! – Jorge Bellido Apr 27 '12 at 10:27
4 rep more and i can vote you up! jaja – Jorge Bellido Apr 27 '12 at 16:11

What makes you believe that the device exists? Entries in fstab don't create devices; devices create devices. Given that you're running a rescue system, I would expect that it's a fairly shite one which doesn't automatically scan for and activate volume groups. Try running pvscan; vgchange -ay and see if your LVs magically reappear.

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I think the device exists because if i do: mount /dev/md1 /mnt i could chroot /mnt and see my folders but /home neither /var but i'll try – Jorge Bellido Apr 27 '12 at 9:42
What does that have to do with whether or not /dev/vg00/var exists? – womble Apr 27 '12 at 9:42
Ahm, yes, Ok. Jaja. Thanks for that advice!! – Jorge Bellido Apr 27 '12 at 9:48
I'm sorry, but i read the other answer before yours but i see now that you answered first, how could it be possible? – Jorge Bellido Apr 27 '12 at 10:30
Because I'm a faster typist. – womble Apr 27 '12 at 10:46

It looks like your running a combination of software raid (mdadm) and volume groups on a linux machine.

In your case the problem looks to be related to your raid manager not detecting and creating the raid volume, or the volume manager not detecting and creating.

This link has an extensive guide how to repair volume groups within software raids:

share|improve this answer
I'll try the 3 commands that i saw below, and if doesn't work, i'll read that document. Added to bookmarks btw. Thanks. – Jorge Bellido Apr 27 '12 at 9:43

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