1. issue an mmadddisk command to add the disk to the file system:

mmadddisk fs1 gpfs12nsd

2. You can rebalance the file system at the same time by issuing:

mmadddisk fs1 gpfs12nsd -r

Note: Rebalancing of files is an I/O intensive and time consuming operation,
and is important only for file systems with large files that are mostly invariant.
In many cases, normal file update and creation will rebalance your file system over time,
without the cost of the rebalancing.

3. To re-replicate data that only has single copy, issue:

mmrestripefs fs1 -r

Add the new NSDs to the file system specifying the -r option to rebalance the data on all disks:

mmadddisk fs0 -F clusterDisksAC -r

위에서 clusterDiskAC는 추가한 디스크를 NSD로 만든 디스크립션 파일을 말한다.