Today I was working with virtual machines and when I tried to install some packages the 2 GB hard disk I configured for this virtual machine reached its limit. By the way, it's pretty amazing a vanilla CentOS 5.4 installation needs almost 2 GB.

Anyway, this is what I did to increase the hard disk space without reinstalling the whole thing:

  1. Create a new hard disk with Virtual Machine Manager. I created it with another 2 GB and selected VirtIO as the disk type.
  2. Start the virtual machine and create a partition in the new disk. /dev/vdb1 is the new disk: 
       Device Boot      Start         End      Blocks   Id  System
/dev/vdb1               1        4063     2047720+  83  Linux
  3. Initialize a physical volume on the new disk: 
    pvcreate /dev/vdb1
  4. Add this physical volume to the logical volume group: 
    vgextend VolGroup00 /dev/vdb1
  5. Extend the logical volume group: 
    lvextend /dev/VolGroup00/LogVol00 -L+1.9G
Rounding up size to full physical extent 1.91 GB
Extending logical volume LogVol00 to 3.84 GB
Logical volume LogVol00 successfully resized
  6. Resize the filesystem: 
    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 1007616 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 1007616 blocks long.

Thanks to LVM now I have 2 more gigabytes on my virtual disk and no reinstallation was needed.