Red Hat Knowledgebase

This article assumes that you have an existing system already using Logical Volume Manager (LVM).

When logical volumes need to be increased in size or number, but there is no more room on the volume group to accommodate this expansion you can add new physical volumes to the volume group. A physical volume is either a new partition or in most cases a new disk. The following example adds a second IDE hard drive, hdb.

To add physical volumes to a volume group you need to the following:

1. Set the partition type to Linux LVM, 0x8e, using fdisk. Make sure you reload the partition table after changing it by either rebooting the machine or running partprobe.

   fdisk /dev/hdb
   

2. The partition needs to be added as a physical volume using pvcreate.

   pvcreate /dev/hdb1
   

3. The physical volume needs to be added to the volume group using vgextend.

   vgextend vg00 /dev/hdb1
   

4. Now the logical volume can be extended using e2fsadm.

Note: It is highly recommended to unmount the file system before resizing any logical volumes. Red Hat currently only supports resizing unmounted file-systems. Trying to resize logical volumes without unmounting the file system can produce unexpected results.