Can you find out the minor device numbers of /dev/vgname/group and/or /dev/vgname/lvol1, e.g. from your notes, old backups or something?
The minor device number for the /dev/vgname/group file should be 0xNN0000, where NN is the unknown part. For the /dev/vgname/[r]lvol1, it should be 0xNN0001 if you did not specify custom LV names.
If you can find out the correct minor numbers, just recreate the device files with mknod:
mknod /dev/vgname/group c 64 0xNN0000
mknod /dev/vgname/lvol1 b 64 0xNN0001
mknod /dev/vgname/rlvol1 c 64 0xNN0001
These device files will be created to the root directory of your troublesome filesystem, so remember to remove them after you've cleaned up this mess.
Now try unmounting the filesystem:
umount /dev/vgname/lvol1
The "fake" device node we created will satisfy the requirements while the filesystem is still there, and after the filesystem unmounts, the real device node will be visible again. As long as the "fake" and the real device node use the same device types and major & minor device numbers, the "fake" device node should even work exactly the same as the real one.
If this trick fails, you can always just ensure that the filesystem will not be auto-mounted at system boot by removing it from /etc/fstab, and then reboot the system.
You can then mount it manually to some other location:
mkdir /mnt
mount /dev/vgname/group /mnt
Then clean up the fake devices, which will now be at /mnt/
:
rm /mnt/group /mnt/lvol1 /mnt/rlvol1
I hope you've now learned your lesson of not mounting your filesystems under /dev :)
MK
MK
