Reverting to a previous level of GPFS when you have issued mmchconfig release=LATEST

If you have issued the mmchconfig release=LATEST command, you must rebuild the cluster. Perform these steps.

Stop all user activity in the file systems.
Cleanly unmount all mounted GPFS™ file systems. Do not use force unmount.
Stop GPFS on all nodes in the cluster:
```
mmshutdown -a
```
Export the GPFS file systems by issuing the mmexportfs command:
```
mmexportfs all -o exportDataFile
```
Delete the cluster:
```
mmdelnode -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.
For the remaining steps, see IBM Spectrum Scale™ in IBM® Knowledge Center, and search for the appropriate IBM Spectrum Scale: Concepts, Planning, and Installation Guide for your release.
Copy the installation images of the previous GPFS licensed program on all affected nodes.
Install the original installation images and all required PTFs.
For Linux nodes running GPFS, you must rebuild the GPFS portability layer.
Reboot all nodes.
Recreate your original cluster using the mmcrcluster command. Run the mmchlicense command to set the appropriate licenses after the cluster is created.
Use the mmchconfig command to restore any previously set configuration settings that are compatible with GPFS 4.1 or below.
Import the file system information using the mmimportfs command. Specify the file created by the mmexportfs command from Step 4:
```
mmimportfs all -i exportDataFile
```
Start GPFS on all nodes in the cluster, issue:
```
mmstartup -a
```
Mount the file systems if this is not done automatically when the GPFS daemon starts.