resize2fs for XFS

For ext2/ext3/ext4 you can run resize2fs /path/to/device after resizing a logical volume with lvextend --size +15G /path/to/device but for XFS can't use resize2fs. You'll get an error like this:

[root@server1 ~]# resize2fs /dev/mapper/server1_storage_vg-vm_backups
resize2fs 1.41.12 (17-May-2010)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/server1_storage_vg-vm_backups
Couldn't find valid filesystem superblock.
[root@server1 ~]# 

Instead, pass -r or --resizefs to lvextend (which seems to call xfs_growfs). If you forget to to this, you can re-run lvextend but of course you'll probably want to set the size explicitly (i.e. --size 30G) rather than as an increase (i.e. --size +15G).