System-config-lvm provides a graphical interface to the LVM tools (and related utilities, including fsck and resize2fs) which is good for non-emergency storage administration. It enables you to manage your logical volume and filesystem configuration with a few mouse clicks, and it prevents potentially- disasterous command-line mistakes such as reducing a logical volume size before reducing the filesystem contained within that volume.

(One word of warning: system-config-lvm does not recognize RAID elements as being in use, and therefore lists them as "Uninitialized Entities". If you are using a LVM-on-RAID configuration, system-config-lvm will let you wipe out RAID elements by making them into PVs. Be careful!)