Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[rolf_eigenheer]

Would you please try this:

Be sure all thumbnails are generated (otherwise do Build missing Thumbnails)
Backup Library
then Restore the Library
then go into Tools\Options\Tree&View\Thumbnails  select ...Build Missing Thumnails...

On my MC25.0.98 the 'Build Thumbnail pane reports " Building Thumbnails (1 of 405778).  This will take a while.
It seems new to me, that the thumbnail cache on the system drive gets flushed on lib restore.

Can anyone confirm ?

[rolf_eigenheer]

It seems that not many are affected by this. It would still be nice if someone could confirm or reject my guess.

[JimH]

Thumbnails are generated from scratch.  Just run it overnight.

[rolf_eigenheer]

Yes, that's what I'm gonna do right now. Is this a new behaviour ? I often do backup and restore, especially when trying new db views.

[blgentry]

You don't have to rebuild thumbnails if you don't want to.  Especially for a test.  MC will dynamically build thumbnails as required.  This will slow things down a bit, but it's not a dramatic slow down.  For testing it really shouldn't be necessary at all, I don't think.

Brian.

[rolf_eigenheer]

You don't have to rebuild thumbnails if you don't want to.  Especially for a test.  MC will dynamically build thumbnails as required.  This will slow things down a bit, but it's not a dramatic slow down.  For testing it really shouldn't be necessary at all, I don't think.

Brian.

Brian, I do not rebuild. MC does something. I just backup and restore the db. After that MC shows red icons instead of the thumbnails.
All Thumbnails have been rebuilt before - means nothing happens when I start 'build missing thumnails. But now after restore, all 400'000 will be done again.
I do want thumnails to be built dynamically. This causes sleeping drives to be wake up, as soon the selected view contains a thumbnail not yet built.
See: https://yabb.jriver.com/interact/index.php/topic,122262.0.html
 
I'm pretty sure MC behaved different in earlier version. Please try, it take less than a minute.

[mwillems]

FWIW, to answer your original question, every time I've done a library restore going back to at least MC 19 had to rebuild the thumbnail cache after a library restore.  So I don't think the behavior has changed in this respect.

[Awesome Donkey]

Assuming the paths for your files don't change, you can backup the Thumbnails folder and restore it after doing a library restore. However, if paths do change, that won't work.

[blgentry]

Brian, I do not rebuild. MC does something. I just backup and restore the db. After that MC shows red icons instead of the thumbnails.

"Red icons".  Do you mean a red circle with a line through it?  That icon means "file not found".  It does not mean anything about the thumbnail.  That is MC's "missing file" indication.  This is fairly normal if your drives are not online and MC is trying to touch the file for the first time.  Or it means that your file paths are incorrect.  Your file paths should be the same if you are using the same machine with the same drive mappings.

If you see a Blue music note icon instead of an album cover, then that means that there is no thumbnail built.  MC should rebuild those, dynamically, almost immediately after you see them (a few seconds).

I do want thumnails to be built dynamically. This causes sleeping drives to be wake up, as soon the selected view contains a thumbnail not yet built.

Oh I see, this is all about waking up your drives again.  Well I'm not sure what to say.  New libraries need their thumbnails rebuilt, so it's going to access the cover art to do that.  If your cover art was on a single drive, maybe that would not happen?  Maybe?  I'm not 100% sure, but I *am* sure that you can put all of your cover art in a single folder instead of having it in every folder with the music files.

I'm pretty sure MC behaved different in earlier version. Please try, it take less than a minute.

Since you asked, I gave it a try.  I see no thumbnails when I switch to a brand new library and restore a backup.  I see blue music notes.  They then build thumbnails rather quickly.  However... when I switched back to my normal everyday library (Main) it had blue music notes too!  I checked Help > System Info > Processing .  I see that almost none of my thumbnails are built.  That's very surprising.  I'm not sure if they showed all built before I did this experiment or not.  If they *were* built before and switching libraries erased them, that would be strange.

Brian.

[rolf_eigenheer]

Since you asked, I gave it a try.  I see no thumbnails when I switch to a brand new library and restore a backup.  I see blue music notes.  They then build thumbnails rather quickly.  However... when I switched back to my normal everyday library (Main) it had blue music notes too!  I checked Help > System Info > Processing .  I see that almost none of my thumbnails are built.  That's very surprising.  I'm not sure if they showed all built before I did this experiment or not.  If they *were* built before and switching libraries erased them, that would be strange.

Would you rebuild all missing thumbnails (Tool\Options\Tree&View\ ...Build missing thumbnails ...) and then try again? Thanks in advance.

[blgentry]

I did the extra experiment that you asked for:

1.  In Main library, rebuild thumbnails.  Wait 35 minutes and all are done.
2.  Delete test library.  Recreate test library.  This switched me to the test library.
3.  Restore (to test library) backup made of Main library earlier today.  After restore is complete...
4.  Help > System information > Processing:  I found that I had 5 thumbnails built, which is "0%".
5.  Immediately switched to the Main library (File > Library > Main).
6.  Help > System information > Processing:  This also shows 0% thumbnails, when a few minutes before (at step 1 above) it showed all built.

So I'm pretty sure that switching libraries, when one of them is a restore of the other, clears the thumbnails of the original library.  I don't remember that happening in the past.  I think I probably would have noticed because my views would have had blue music notes when I switched to my main library.  But it's honestly been quite some time since I did any testing like this, so it may always have been this way.

If you still have MC24 or MC23 installed, you might try there to see if the behavior is different or not.

Brian.