Migrating to IBM Spectrum Scale 4.2 from GPFS 3.4 or GPFS 3.3

Node-at-a-time migration is not available when migrating to IBM Spectrum Scale™ 4.2 from GPFS™ 3.4 or GPFS 3.3. The cluster must be completely shut down and all nodes migrated at the same time. If this is not acceptable, and your current level is GPFS 3.4, you may want to consider an intermediate migration to GPFS 3.5 first.

To migrate a cluster to IBM Spectrum Scale 4.2 from GPFS 3.4 or GPFS 3.3, perform these steps:

Stop all user activity in the file systems.
For information about how to stop and then unmount NFS running over GPFS file systems, see Unmounting a file system after NFS export in IBM Spectrum Scale: Administration and Programming Reference.
Cleanly unmount the mounted GPFS file system. Do not use force unmount.
Follow any local administrative backup procedures to ensure protection of your file system data in the event of a failure.
Stop GPFS on all nodes in the cluster:
```
mmshutdown -a
```
Run the appropriate de-installation program to remove GPFS from each node in the cluster. For example:
- For Linux nodes:
```
rpm -e gpfs.gpl gpfs.base gpfs.docs gpfs.msg.en_US
```
- For AIX® nodes:
```
installp -u gpfs
```
- For Windows nodes, open the Programs and Features control panel and remove IBM General Parallel File System.
  Note: To upgrade a GPFS 3.4 Windows node (SUA based) to GPFS 4.1 Standard Edition (Cygwin 64-bit based), proceed as follows:
  1. Uninstall GPFS 3.4 and reboot.
  2. Uninstall the GPFS 3.4 license.
  3. Disable any SUA daemon, such as OpenSSH, that might have been configured. Do not uninstall SUA yet, or you may lose GPFS configuration information.
  4. Install the 64-bit version of Cygwin. See Installing the 64-bit version of Cygwin for more information.
  5. Install gpfs.ext-4.1.1-Windows-license.msi.
  6. Install gpfs.ext-4.1.1.x-Windows.msi
  7. Install IBM® GSKit for GPFS.
  8. Uninstall SUA completely.
Copy the installation images and install the GPFS product on each node in the cluster as described in Installing GPFS on Linux nodes, Installing IBM Spectrum Scale on AIX nodes, or Installing IBM Spectrum Scale on Windows nodes.
Note: For Windows migrations, it is required that all IBM Spectrum Scale 4.2 administration commands are executed from the 4.2 node.
Start GPFS on all nodes in the cluster:
```
mmstartup -a
```
Mount the file systems if this is not done automatically when the GPFS daemon starts.
Proceed to Completing the migration to a new level of IBM Spectrum Scale.