Screwed up my catalogue previews in lr3

mrjames

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Hi, I ran out of disk space and recently found that I have a 0gb lrdata preview cache, not huge but big enough on my 500gb drive!

I have 30k images in my catalogue and most of them are archived, so not longer need the 1:1 previews (I can just render on the fly anyway), so I moved my 30gb lrdata previews cache to an external drive and set my computer to re-render 'standard previews' (discarding 1:1 previews didn't shrink the cache at all?), and after 10 hours it had done 10%, so I killed that process and moved the cache back, not sure how to sync it back up with the catalogue as now I have no previews. If I run a 'render previews' process will it read the original previews or will it just render new ones, have I ballsed up my catalogue?
 
bit confused by your post, but you can set an opition in your LR preferences to delete previews over 30 days old. This will save you alot of space
 
bit confused by your post, but you can set an opition in your LR preferences to delete previews over 30 days old. This will save you alot of space

I have it set to that, but even when I manually deleted all the 1:1 previews the size of the lrdata file didn't really change much, if at all

apparently it's a bug, so when you delete 1:1 previews rather than giving the new space back to the system it keeps hold of it but creating new previews just uses the space freed up by deleting the old previews, does that make sense?

Anyway my question basically is how do I force lightroom to utilise old preview data rather than trying to render new ones

eitherway the lesson learned here is don't mess with the catalogue


this is a highly technical question that might be beyond the scope of most light room users...
 
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sounds about right, quite a lot of databases keep deleted space rather than having to shrink and grow every five mins.

when you run a catalogue backup theres an option to "optimize catalogue after backing up", see if that reclaims the space.
 
Did you back up your catalog prior to making these changes?

The previews are stored in your catalog so the previous ones will be saved within the catalog file
 
thanks for the help guys
I did back it up

but I fixed the issue by moving the lrdata file back, then running a 'render standard previews' task, it scans the 'existing previews' then renders the previews it doesn't have, at first I was concerned it was going to render all 25gb of previews again but it doesn't, after about 10 minutes my lrdata file had gone up about 1gb but that was probably just due to files that didn't have a standard preview anyway

so it seems you can just move the lrdata folder back and lightroom kind of sorts itself out, interesting

regarding the decrease in size when deleting 1:1 previews, it does shrink, but there is a big delay between running the task and seeing the results, I ran it and saw no change, came back an hour later and it had shrunk but not by much, because I delete 1:1's after 30 days there was only about 1gb worth of previews anyway

the solution to this, don't use small capacity SSD's
I was planning on moving to a 120gb SSD with a 750gb drive for data, so i'll probably put the lrdata file on the big drive and not worry about it's size
 
regarding the decrease in size when deleting 1:1 previews, it does shrink, but there is a big delay between running the task and seeing the results, I ran it and saw no change, came back an hour later and it had shrunk but not by much

IIRC that's a deliberate feature.

If you delete previews and then undo they magically come back instantly. That's because it only pretends they aren't there and schedules a delete for several minutes in the future.

Sadly there are a number of foibles in the preview code and this behaviour combines with them on occasion to mean you are running off old previews.
 
IIRC that's a deliberate feature.

If you delete previews and then undo they magically come back instantly. That's because it only pretends they aren't there and schedules a delete for several minutes in the future.

Sadly there are a number of foibles in the preview code and this behaviour combines with them on occasion to mean you are running off old previews.

great info

thanks!
 
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