Lost recently added album after a rescan

[Lio84]

I just added 1 album on my NAS QNAP HS 251 +, and corrected some tags on another multidisc album.
After a surprisingly long rescan (5 minutes), Naim app shows 70 recently added/last day albums which are not recent at all, all belonging to the same genre.
Not the first time it happens
I am running Minimserver 2 on a QNAP NAS
Any ideas ?

[simoncn]

If MinimServer can't find the cache file from the previous rescan or if there is some problem reading this file, MinimServer isn't able to know what files have been added since the last rescan. This would also explain why the rescan took longer than expected.

This does not explain why you are seeing "last day" albums which are not from the last day. Without a cache file, MinimServer uses the modification dates of all files to build the recently added index, so the "last day" index should only contain files with a modification date in the last day.

Is it possible that the system clock was reset accidentally to some time in the past? If so, some older albums could be picked up as "last day" because they have modification dates newer than the current clock time. This could also possibly explain why MinimServer had a problem reading the cache file.

Are there any messages in the MinimServer log that might provide a clue about what has happened?

[simoncn]

Did you rename or move any files or folders before doing the rescan? This would cause all renamed or moved files to be identified as added in the last day.

If this isn't the reason for the problem, please post the added-dates.txt and added-files.txt files from the MinimServer/recent folder. This should provide more information about what has happened.

[Lio84]

(08-08-2022 07:10)simoncn Wrote:  Did you rename or move any files or folders before doing the rescan? This would cause all renamed or moved files to be identified as added in the last day.

If this isn't the reason for the problem, please post the added-dates.txt and added-files.txt files from the MinimServer/recent folder. This should provide more information about what has happened.

Thanks for your reply

I did'nt move or rename any files except for the folders "Jeanine De Bique/Mirrors", "Handel-Giulio Cesare [Jacobs]" and "Teresa Berganza-Les jeunes années [Ind. Diapason]"

All the other folders in "/share/Multimedia/Musique/Variété française" remained unchanged (no changes since years in these folders)

I have attached the 2 files

[simoncn]

Thanks for these files. I have looked at them and I think I understand what has caused this problem.

On Linux, the order of scanning folders is not fixed but can change when a folder is renamed. This can cause the order of scanning to get out of sync with the order of folders in the MinimServer cache and some files can be incorrectly identified as newly added because the folders containing these files are now being scanned in a different order.

This change to scanning order does not just affect the folders that are renamed but can also affect all other folders in the same parent folder (/share/Multimedia/Musique/Variété française).

The next update to MinimServer will contain a fix that should solve this problem. Thank you for letting me know about this.

[Lio84]

(09-08-2022 13:29)simoncn Wrote:  Thanks for these files. I have looked at them and I think I understand what has caused this problem.

On Linux, the order of scanning folders is not fixed but can change when a folder is renamed. This can cause the order of scanning to get out of sync with the order of folders in the MinimServer cache and some files can be incorrectly identified as newly added because the folders containing these files are now being scanned in a different order.

This change to scanning order does not just affect the folders that are renamed but can also affect all other folders in the same parent folder (/share/Multimedia/Musique/Variété française).

The next update to MinimServer will contain a fix that should solve this problem. Thank you for letting me know about this.

Thanks, I will let you know if this happen again

[Lio84]

Hello

Exactly the same problem today as in august: all my recently added album cancelled replaced by others (not recent). Particularly painful
Same phenomena: surprinsingly long rescan after adding 4 new albums by copy/past from my laptop to the NAS.
I usually prepare the albums on my laptop with mp3Tag, then copy the albums in the appropriate folder in the NAS by wifi.

My operations were:
- Add album 1 to the NAS by copy and past from my laptop
- Add album 2 to the NAS by copy and past from my laptop
- realize that albums 1 and 2 have a possible mistake in the tags and delete album 1 and 2 in the NAS
- Correct the wrong tags in albums 1 and 2 on the laptop
- Select and add albums 1,2,3 and 4 in one shot by copy and past from my laptop
- rescan (quite long)
- All my 70 recently added albums cancelled !

I did only one rescan during the process at the end

Running MinimServer 2.1.2 update 218 on QNAP HS 251+

Is there a way to restore the recently added album ?

[simoncn]

Thanks for this detailed description of the events leading to this situation. From this description and from the files you posted, I am sure the problem is caused by a change to the ordering of folder scanning in the Linux filesystem when you did the copy 2 folders / delete 2 folders / copy 4 folders sequence. This caused MinimServer to incorrectly detect some folders as new that are not in fact new.

I have a fix for this problem but testing it is a challenge because of the difficulty in creating the unusual situation where the folder scanning order changes. I will try the copy/delete/copy sequence you have used to see if this enables me to reproduce the problem and test the fix.

If you stop MinimServer, delete the added-dates.txt file and then restart MinimServer, this should restore some of your lost "recently added" information. This will use "last modified" dates to rebuild the "recently added" information, which should produce a result that is fairly close to the correct "recently added" dates.

When you do this, you might see some incorrect entries for files you have retagged recently but are not recently added. You can remove these by stopping MinimServer, manually editing the added-dates.txt file to delete any lines for retagged files, then restarting MinimServer.

Alternatively, if you have a recent backup of the added-dates.txt file, you can stop MinimServer, replace added-dates.txt with your backup and restart MinimServer.

[Lio84]

I have stopped Minimserver, deleted the added-dates.txt file and then restarted Minimserver following your advice, and it works quite well. My recently added album are restored. Thanks !! I will avoid deleting folders until the this problem is fixed

[simoncn]

There is a fix for this problem in MinimServer update 219, just released. I have set up an environment that enables me to test out-of-order folder scanning and the fix seems to be working OK.

At present, update 219 is not installed automatically. It can be installed manually from the About dialog (Show updates) or from the Packages tab of the Properties dialog.