Making a larger partition from new disk space
Enlarge the partition with parted
parted (select disk) resizepart # 100%
LVM: we need to tell the LV subsystem about the new disk space; we do this by first extending the physical volume which occupies the partition:
then the logical volume
lvresize -r -l 100%PVS /dev/mapper/XXXXXXXX
df -h still shows the wrong size then the above command didn't expand the FS as it should. This could be due to version issues of the tools. Run
resize2fs on the mapped volume.
Moving disk space around
File system check the volume to be shrunk, then shrink it by several GB more than you will be reclaiming. It will be enlarged later. Shrink the volume by your desired amount.
Assuming an end goal of 200G
e2fsck -f /dev/foo/roo resize2fs /dev/foo/roo 180G lvreduce -L /dev/foo/roo 200G
Enlarge your target voume to take all now free space
lvresize -r -l 100%PVS /dev/foo/boo
Fix the filesystems
resize2fs /dev/foo/roo resize2fs /dev/foo/boo