Issues with replacing hard drive

I am running out of hard disk space, so I’ve ordered an 18 TB drive to replace two (2) drives - one having been used for “Various Artists” compilations and the other for all other albums. Rather than placing the “various artists” compilation albums on a separate disk they will now be in a separate “various artists” directory. Otherwise the directory structure will not change. My “other albums” have been (and will be) organized with the album artist being the directory, the album name being the first subdirectory and, if the album consists of more than one disk, then under that subdirectory there will be numbered sub-sub-directories for each disk. Roon hasn’t recognized those disk sub-directories as parts of the same album, so I’ve needed to “merge” the disks manually.
I plan to copy all the files from the existing two drives directly from the Rock over to the new 18 TB drive (with “various artists” being placed into a new “Various Artists” directory) and then remove the old drives and attach the new drive to the Rock.
Questions for all the experts here: Can Roon keep this organization and all the “merged albums” (meaning multi-disk albums) with the new 18 TB single disk, or will I once again need to “merge” the disks manually? Is there an easier way to assure that Roon recognizes the separate disks as being part of one album? (File metadata correctly identifies the disks.)

Based on my experience, the answer to your question is “no”. You will need to “merge” the disks manually once again.
Alternatively, to get rid of this manual work, put all the files of a multidisc album in one folder.

If you follow the Move Music FAQ linked below you should be okay. In essence, you will keep your two storage locations but edit them to the new individual base directories. That should keep all your edits/play counts, etc the same.

Am I reading this right? After waiting for any file imports to have completed, I just copy the files to the new location (my new 18TB drive), remove the old storage folders from Roon, plug in the new drive, add the new watched folder location, and voila!

Maybe I set up the new drive by shutting down the Rock and moving everything (two existing external USB drives and new 18TB USB drive) to my Windows machine to do the copying. (These disks have been, or will be, exFAT formatted.) I could set up two separate “prime” directories - “Various Artists” and “Named Artists” - so I can thereafter set up two separate Roon watched folders as I have now.

Does Roon use the file name for identifying the music? Can I rename the files and remove the disk sub-directories, or must I keep the existing file names and sub-directories? What happens to my marked favorites and my playlists?

Rugby, I really appreciate the help here. Thank you!

By my logic, these instructions lead directly into the new read with loss of any manual additions that were not automatically recognized by Roon in the old location. Roon simply detects a new location again and adds them.

I wish it were different, but I’m afraid the old location will just have deleted content unless the library is not cleaned up, in which case everything can reappear.

Writing the music to new disks is like starting over.

How must the library be “cleaned up”?

How would you handle this?

If I remove the disk sub-directories and have all files from a single album in a single directory, won’t Roon see these files as a single album (no need to merge)? Should I just leave everything as is (as far as the file directory structure is concerned - with the existing disk sub-sub-directories)?

Am I going to lose my 46 playlists and 2511 tracks marked “favorite”? If so, is there a way to avoid the loss?

I would start with a mini test of a few pieces of music following the Roon instructions.

If these are still in the database after closing, moving and reconnecting with all manual changes, I would be puzzled. Of course, the old hard drive is not connected in the process and will only come back if the test goes better than expected.