Filesystem changes and playlists

Heres a question about playlists and how roon identifies albums. sometimes one needs to modify the music file repository, and it is useful to know what will impact the roon playlists. After some experiment, I think these statements are true:

  • renaming an album usually does not impact the playability of tracks from that album which are on a playlist. (tested: put track on playlist, rename album, force rescan, play track from playlist)
  • moving an album to a different file directory usually does not impact playability of tracks from that album which are on a playlist. (tested similarly by playing after moving album)
    -moving an album between network shares makes any tracks on that album which are on any playlists unplayable.

I think this says something about what quantities roon is hashing to create an album id. It would be useful for the knowledge base to have some discussion of this, and some guidelines for what music repository changes can be safely made without disrupting playlists, and what changes cannot. with regard to the thread on exporting playlists (Playlist (m3u) Export WITHOUT the music files - #24 by jim_hamilton) repairing large playlists when they are affected by needed fileserver changes is another reason for exporting playlists without the overhead of also exporting music files.

I think if you disable RoonServer first so it is not watching the shares, it will treat the moved file as the same and not new when it is restarted. Need to test that though to be sure.

thanks for the suggestion. maybe I wasn’t very clear. If I moved an album within a network share, even with the server running, it didn’t cause a problem: tracks in that album on the playlist still worked. apparently the way roon creates a id (likely a hash) for the album is independent of the file/directory location (this is great). If I moved the file across network shares (still with the server running), it was no longer available to the playlist. this makes me think the album id is somehow tied to the network share. (I have 2 network shares defined to roon, but both are in the same linux filesystem).
I will try your test of moving a album across network shares with the roonserver stopped, then restarting the roon server and seeing if the playlist track is still viable. my guess is no.

ok, here are some more test results, this time using server shutdown as @rugby suggested.

but first, why am I doing this and asking these questions? Well, I have a number of large-ish playlists (500-2500 tracks each). anyone who has used playlists much knows that over time they degrade, unless you have a very static situation. For example, I might notice I mis-spelled “mississippi john hurt” in an album title and changed it, not thinking that this might affect some playlists. Or I might re-arrange directories or move an album, etc. In my case I have a perl script that accepts a playlist, adjusts for differences in mount points depending on the playlist source, and attempts to read each track, reporting errors. Roon (correct me if I’m wrong) has no such tools. (as an aside, this is one reason why I’d like to export playlists from room absent all the music files). So, what changes can I make to my music repository without causing side effect errors in roon playlists?

the test. (if I do more of this I’ll make a small test directory. this is painful with a large music repository because of all the rescans. For all tests, start by adding a track to a roon playlist (my case: beatles rubber soul/nowhere man). test that it plays
test 1: moving albums.
1a. shut down roon server
1b. move the rubber soul album to another directory
1c. start roon server (which does rescan)
1d. test if playlist still works. verify using fileinfo in roon that roon really sees the correct, new location
test 2: renaming albums
2a. shut down roon server
2b. rename the rubber soul album (I named it xpqg)
2c. restart roon server (does rescan)
2d. test if playlist still works. verify using fileinfo in roon that that roon really sees the directory name as xpqg.
test 3: moving albums across network mounts
3a. shut down roon server
3b. move rubber soul album to a directory that is under a different roon network mount point.
3c. restart roon server (does rescan)
3d. test if playlist still works. verify using fileinfo that roon really sees the album in the new network share location.

results: my hats off to roon. these all work. scan can relink database information to filesystem location.
Note that test 3 failed when I did it without restarting the roon server, though I’m not sure my force rescan was done on both mount points. Based on this limited testing, with regard to my original question, playlist integrity can be maintained through file name changes and album location. So I’m just asking that this be made clear in the knowledge base (assuming I’m correct), and for a clarification or guidelines from roon about what music filesystem changes will affect playlists, and what changes are safe.