How can I resize a LVM partition in Red Hat without lose of data?

Question

My partition detail is like this

/dev/mapper/VolGroup00-LogVol00
                       57G  8.8G   46G  17% /
/dev/mapper/VolGroup00-LogVol05
                      259G  7.0G  239G   3% /home
/dev/mapper/VolGroup00-LogVol02
                       19G  493M   18G   3% /var
/dev/mapper/VolGroup00-LogVol03
                       19G  458M   18G   3% /tmp
/dev/mapper/VolGroup00-LogVol04
                      9.5G  152M  8.9G   2% /opt
/dev/sda1             965M   33M  883M   4% /boot
tmpfs                 7.7G  3.7G  4.0G  48% /dev/shm

I want to increase the size of the / by reducing the size of the /home partition, without lose of data in the / and home.

Can anybody help me in solving this issue?

Solution 1

• Boot with a live distro (lvm capable)
• don't mount your lvm partitions
• fsck LogVol00 and LogVol05 (twice this step)
• lvreduce -L-xG /dev/VolGroup00/LogVol05
• resize2fs -p /dev/VolGroup00/LogVol05

do the same for /dev/mapper/VolGroup00-LogVol00 with lvextend instead of lvreduce

Solution 2

I second vishaal's answer, however he left out a couple steps..as well as the fact you can do this with linux rescue

1. Boot into linux rescue
2. skip mounting
3. run lvm vgchange -a y (in rescue mode you preface the commands with lvm)
4. verify visibility by OS with ls /dev/VolGroup00/

5. The rest is much like vishaal described, but you'll want to force the e2fsck with a -f ie: e2fsck -f /dev/VolGroup00/LogVol..

6. IMPORTANT, you resize the filesystem before you reduce the volume, so..

7. resize2fs -f /dev/VolGroup00/LogVol.. 40G (if you wanted the size to be exactly 40G)
8. lvm lvreduce -L40G /dev/VolGroup00/LogVol.. (again if you wanted the size to be exactly 40G and not reduced by 40G)

Mine is simply an addition to what advice vishaal has already given.

Comments

[Allen]

It's a good idea to leave unallocated space in the volume group to hand out to needy LVs in future. It's part of the benefits of using LVM. Otherwise you end up in this situation.

[Scott Pack]

This assumes Charly is using ext. While most filesystems can be shrunk no problem, XFS (for example) can only be grown, never shrunk.

[ben]

:D sysadmins are creatures of habit. Hadn't heard of that, thanks!!