hi,

i am trying to shrink /usr (which is a logical volume). i managed to unmounted /usr but when i tried to use lvreduce, it did not work because the location of lvm is in /usr/sbin/lvm. therefore, when the system was in single mode and I started lvm, there was no response. what should i do to keep lvm working even after unmounting /usr?
(OS Fedora 8) thanks in anticipation.

Try moving lvm and its dependants to /sbin. In fact, if I were you, I'd consider moving all of /usr/sbin (and its dependants) to /sbin.

You should be aware that /usr (the "unix system resources" directory) is, normally, considered an essential part of the system, and many applications will expect to find their needed resources in that directory, so removing it may break many of your applications.

<edit>
Also, your use of the phrase "shrink /usr which is a logical volume" is somewhat strange. Normally a logical volume is an abstraction layer between your physical hardware and your file system. It is primarily used so that physical changes can be made without much impact on the structure of the file systems.

To say that "/usr is a logical volume" implies that:
1) /usr is in it's own partition.
2) That partition is a separate entry in it's own logical volume.
3) The partition is not full
4) The lvm tools, for some reason you don't address, are not adequate to shrink that logical partition.

Also, to say that you "unmounted /usr" implies that /usr was, in fact, on a separate partition and mounted by, presumably, an entry in /etc/fstab like this:Both usages seem fairly sophisticated and quite unusual.

Are you sure that /usr is, in fact, on a separate (logical) partition on your system?
</edit>

Don't do the work on the active system - use a LVM aware rescue or liveCD. The first Fedora disk or Knoppix should do.

Thanks a lot PTrenholme

But how I can do that without messing up lvm's dependencies?
I already copied and pasted very carefully every single file connected with lvm from /usr/sbin to /sbin. Then, I unmount /usr, started the system in a single mode. when I tried to start lvm, the utility response was that lvm could not locate its dependancies.

Yes you are right about the above points
/usr is not full and there is plenty of space in it. Therefore, I need to shrink it to expand /home.
The lvm tool that I am trying to use is lvreduce. the main problem is that if lvm did not start, lvreduce would never work.

Yes /usr is on a separate logical volume in order to have the flexibility of change its size if the system requires that.


Thanks again.

Thanks syg00

I will keep your advise in mind and I have verified B-A-C-K-U-P, thanks to tar.

thanks again

O.K., that sounds like you know what you're doing.

The simplest solution to your problem is to use a LV-aware LiveCD, boot from it, and use the LV tools to do the shrinking.

If, for some reason you don't want to do that, try:

1) Copy /usr to, say /Usr on another drive or partition.
2) Unmount /usr and the /Usr copy
3) Mount the /Usr copy as /usr
4) Shrink the (now unmounted) /usr
5) Unmount the /usr copy
6) Remount the "real," now shrunk, /usr
7) Test
8) Remove the temporary /Usr

and (I hope) you're golden again.

Good luck -- and keep that backup handy!

I couldn't implement the second solution because I do have enough free space to accommodate the
/usr.
the first solution solved the problem.
many thanks