Migrating application from an old system to a new system

After all the data is migrated from the old system to the new system by recursively running the prefetch command. In some cases, data might be created recently on the old system. This data must be prefetched from the old system.

Check the uncached data and restart the prefetch operation one last/final time to bring the latest/remaining data from the old system to the new system.
After all the data is migrated to the new system, you can stop the migration and can break the AFM relationship.

Check the status of migrated data on the AFM fileset (new system)

All the data from the old system is already migrated to the new System (AFM cache site). Do the following steps to check if any data is not migrated to the new system and prefetch the remaining data:
- Old method before 5.2.2
```
mmafmctl fs1 checkUncached -j ro1
```
- New method
```
mmafmctl fs1 checkUncached -j ro1 --check-unmigrated
```
  A sample output is as follows:
```
Verifying if all the data is cached. This may take a while...
mmchfileset: [E] Uncached files present, run prefetch first
Directories list file: /var/mmfs/tmp/cmdTmpDir.mmchfileset.3241/dir-file.mmchfileset.3241
Orphans list file: /var/mmfs/tmp/cmdTmpDir.mmchfileset.3241/orphan-file.mmchfileset.3241
```
If any data is still not migrated to the new system, then the mmafmctl command generates a list files that can be used to run the one last prefetch command.

To prefetch remaining data by using the generated list files, issue following commands:

mmafmctl device prefetch -j ro1 --dir-list-file /var/mmfs/tmp/cmdTmpDir.mmchfileset.3241/dir-file.mmchfileset.3241

mmafmctl device prefetch -j ro1 --list-file /var/mmfs/tmp/cmdTmpDir.mmchfileset.3241/orphan-file.mmchfileset.3241

To check the prefetch status, issue the following command:
```
mmafmctl device prefetch -j ro1
```
Note:
- Wait for all in-memory data to be flush to the disk.
- The data that is required to run the application is now migrated to the new system Therefore, post conversion of the AFM fileset from RO mode to LU mode, the application can be moved from the old system to the new system and the operations can be restarted. The prefetch operation migrated most of the data from the old system at this time.
- Perform either new method or the old method, not both.
- Changing to LU mode will allow updates to the fileset only. Data will not be replicated back to the source.
Disable AFM LU-mode fileset to convert it to GPFS independent fileset. You can disassociate the AFM relationship from the fileset to remove all AFM tunables or information and relation is deleted.
You can use this fileset as a local GPFS independent fileset without the AFM replication.
```
mmchfileset fs1 ro1 -p afmTarget=disable-online
```
The output is as follows:
```
Warning! Once disabled, AFM cannot be re-enabled on this fileset. Do you wish to continue? (yes/no) yes
Warning! Fileset should be verified for uncached files and orphans. If already verified, then skip this step.
Do you wish to verify same? (yes/no) no
Fileset ro1 changed.
```
For more information about disabling the AFM relationship, the Disabling AFM section in the IBM Storage Scale: Concepts, Planning, and Installation Guide.