Hello Immich chaps and chapettes,
In the hope that this may help others move the datasets from the original 7 required (Backups, Videos, Library, Profile, Thumbs, Uploads, PGData and MLData), to the new 3 datasets suggested by the latest Immich app (Userdata, PGData and MLData).
After following the steps below, you will end up with 3 data
The steps to follow are as below.
1 - Stop Immich app
2 - Create new Userdata Dataset with the same ACL permissions of the current datasets.
3 - Copy all the lines from my example below and replace the paths with yours as required.
4 - Open Shell and take control as Sudo and paste each line below separately to ensure no errors occur.
5 - As you can see below, we are leaving the PGData and MLData be and outside of the Userdata dataset.
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/backup/ /mnt/SSD-Storage/App_Config/Immich/userdata/backups
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/videos/ /mnt/SSD-Storage/App_Config/Immich/userdata/encoded-video
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/library/ /mnt/SSD-Storage/App_Config/Immich/userdata/library
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/profile/ /mnt/SSD-Storage/App_Config/Immich/userdata/profile
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/thumbs/ /mnt/SSD-Storage/App_Config/Immich/userdata/thumbs
rsync -avh --progress /mnt/SSD-Storage/App_Config/Immich/uploads/ /mnt/SSD-Storage/App_Config/Immich/userdata/upload
6 - When you have finished Rsyncing the datasets above into the new Userdata dataset, go to edit the app and deselect the Old Storage Configuration, and select the new Data Storage Host path to the new Userdata dataset.
7 - Leave the PGData and ML data unchanged. You want these to be outside of the Userdata dataset.
8 - Update and start Immich app. It should successfully start if none of the new folder name were changed. If Immich keeps restarting, view the Server logs and find out what folder is it complaining about and ensure that the rsync command for that is creating the same folder.
When this is all done and Immich has successfully started, you are welcome to delete the old Datasets. My advice is to keep them for a while and ensure that there are no issues with the new structure and delete when safe.
This is my new Storage config in case it helps with visualising the change.
If for some reason you can not start the Immich app, you can always move back to the old storage configuration while troubleshooting the issue.
Hope this helps.