There are several Howtos on the net, which tell you to do the following if you want to create LVM snapshots if you have XFS filesystems on your logical volumes:

xfs_freeze -f /mnt/xfs
lvcreate -L 10G -s -n fs_snap /dev/VolGroup00/LogVol01

If you try that on a system without LVM2, the following will happen: lvcreate will hang until you do an

xfs_freeze -u /mnt/xfs

in a second terminal. After that lvcreate will create the snapshot for you.


If you use LVM2 (like CentOS 4 or CentOS 5 do), lvcreate will do the freezing for you.


lvcreate -L 10G -s -n fs_snap /dev/VolGroup00/LogVol01

will freeze your xfs filesystem before creating the snapshot.