1) Backup your existing volume files.
2) Use glusterfs-volgen to generate new volume files that take into
account the new disks.
3) Make a copy of the client volume file and modify the section
corresponding to the distribute volume in the copy to have the following
options:
option lookup-unhashed on
option unhashed-sticky-bit on
option use-readdirp on
and remove statprefetch from client volume file.
4) Restart the glusterfsd process/es so that the new disks/directories
are exported.
5) Have a temporary mount using the modified client volume file.
6) Run the scale-n-defrag script (edit MOUNTPOINT to reflect temporary mount directory)
7) Once re-balancing is done, you can umount the temporary mount.
8) You can now mount using the unmodified client volume file (generated
in step 2).