how to resize linux lvm volumes

WARNING!!! this procedure is untested on production hosts!!!

boot with a live disk so the system disks are not in use, then one can reduce the size of a LVM logical volume with the following:

lvm vgchange -a y
e2fsck -f /dev/VolGroup00/LogVol00
resize2fs -f /dev/VolGroup00/LogVol00 10G
lvreduce -L10G /dev/VolGroup00/LogVol00

the -f switch to resize2fs has been added since one may recieve the message Please run e2fsck -f /dev/VolGroup00/LogVol00 when running resize2fs, even after an fsck has been done.