How to resize or expand LVM partitions

A few week ago, I installed FC6 on my laptop and my slash (/) partition started to run out of space. So I decided that I would shrink my big partition and expand my / partition. Fortunately, I installed FC6 using LVM2 (Logical Volume Manager) which makes it very easy to resize partitions without even rebooting.

Here is how I did.
My partition was like this:

Filesystem	1K-blocks	Used	Available	Use%	Mounted on
/dev/mapper/VolGroup00-LogVol00	7935392	6773500	752292	91%	/
/dev/sda5	497829	20904	451223	5%	/boot
tmpfs	1037084	0	1037084	0%	/dev/shm
/dev/mapper/VolGroup00-LogVol01	70877776	14988144	51045372	23%	/home

My / partition is about 8 Gb and my /home partition is about 71 Gb.

For /home, I did:

1. umount /home
2. e2fsck -f /dev/VolGroup00/LogVol01
3. resize2fs /dev/VolGroup00/LogVol01 69G
4. lvreduce -L-2G /dev/VolGroup00/LogVol01
5. mount /home
   

For / partition, I did:

1. lvextend -L+2G /dev/VolGroup00/LogVol00
2. resize2fs /dev/VolGroup00/LogVol00

e2fsck and resize2fs belong to package e2fsprogs-1.39-7.fc6.

resize2fs has the ability to resize mounted partitions.
From the manual of resize2fs:

[...] If the filesystem is mounted, it can be used to expand the size of the mounted filesystem, assuming the kernel supports on-line resizing. (As of this writing, the Linux 2.6 kernel supports on-line resize for filesystems mounted using ext3 only.). [...]

[root@tosca ~]# resize2fs /dev/VolGroup00/LogVol00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/LogVol00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/LogVol00 to 2400256 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 2400256 blocks long.

I finaly end up with the following partionning:

Filesystem	1K-blocks	Used	Available	Use%	Mounted on
/dev/mapper/VolGroup00-LogVol00	9299624	6779304	2043564	77%	/
/dev/sda5	497829	20904	451223	5%	/boot
tmpfs	1037084	0	1037084	0%	/dev/shm
/dev/mapper/VolGroup00-LogVol01	68877776	14999888	51033628	23%	/home

Some useful LVM commands (package lvm2-2.02.06-4):

• lvmdiskscan
  
• vgdisplay
• pvdisplay
• lvdispay
• vgcreate
• pvcreate
• lvscan
• pvscan
• vgscan
  

Some useful links:

• http://www.tldp.org/HOWTO/LVM-HOWTO/
• http://www.hccfl.edu/pollock/AUnix1/LVM.htm