15 Replies Latest reply on Nov 24, 2015 11:15 AM by dj_paige

    Delete Preview File?

    mike240 Level 2

      I have just got a new computer and have transferred all relevant Lightroom files to a freshly installed CC Lightroom. All went well and it’s up and running with all my settings, previews etc. Phew!

       

      However, to my horror, when I was moving my previews I noticed that it was a 130GB file. I have nearly 100,000 photos. And, obviously, I’m keen to reduce the size of that preview file because I don’t want it hogging such a large slab of my (C:) SSHD.

       

      I have done a lot of reading up on this issue and understand about the problem with assuming that Lightroom will delete previews after a designated period lapses (in my case, set at 30 days). Changing the settings in ‘file handling’, within ‘catalog settings’, only achieved a 8GB reduction in the overall preview file size. I’ve not come across anyone claiming to have cracked this issue in a satisfactory, long term way.

       

      I’m close to deciding to delete the entire preview file and just put up with having to build previews of each photo as and when I need to work on them. It just means sitting there watching an image as it’s ‘loading’

       

      But, before I do that I just wondered whether there is a way to delete just the older, say 80%, part of the file. To be more specific, I have one catalogue with three ‘folders’. Each folder has its dedicated external hard drive. A perfect solution would be to just delete the previews of the photos on the two older drives and leave the previews of the current newer drive in place. However, having had a quick look at the file structure of the previews, it’s not that clear to me how to identify what is what.

       

      Has anyone gone down this route with success? If not, is there anyone with any suggestions?

       

      Mike

        • 1. Re: Delete Preview File?
          Mohit Goyal Adobe Employee (Admin)

          Hi mike,

           

          You can move the Previews.Lrdata to any other drive, it will not cause any loss of images, its a cache that gets created at the background in the Lightroom folder which save at Picture folder.

           

          Regards,

          ~Mohit

          • 2. Re: Delete Preview File?
            mike240 Level 2

            mohgoyal@adobe.com wrote:

             

            Hi mike,

             

            You can move the Previews.Lrdata to any other drive, it will not cause any loss of images, its a cache that gets created at the background in the Lightroom folder which save at Picture folder.

             

            Regards,

            ~Mohit

             

            Thanks Mohit.

             

            That sounds straight forward. But, will it cause any slowness in the 'loading' of images into loupe view or opening up in Develp Mode? I was always under the impression that we should always have the Previewslrdata files sitting alongside the Catalog files (ie within...Windows-c:\Users(Mike)\Pictures\Lightroom). I understood that this was so that it kept lag time to a minimum.

             

            I'd welcome some assurance on this.

             

            Thanks,

             

            Mike.

            • 3. Re: Delete Preview File?
              dj_paige Level 9

              Normally the previews need to be on the fastest disk, otherwise you may see some slowdowns in Lightroom. Nevertheless, it might still be worth a try to see if the slowdown is tolerable. There is a way to access previews via even if they are not in the same folder as the catalog itself, but I do not know the details. You can either search the forums or wait until someone who knows the details replies here.

               

              Simply moving the previews to another drive, without the aforementioned method of accessing the previews, doesn't really help you at all, Lightroom will just regenerate the previews on your SSD, saving you no space at all.

              • 4. Re: Delete Preview File?
                Mohit Goyal Adobe Employee (Admin)

                You can try rename the the Previews.Lrdata to Previews.Lrdata.old and open Lightroom and see how it responds.

                 

                If it works fine with no issue you can move the Previews.Lrdate to any other drive or trash it as Lightroom regenerates it whenever you open it.

                 

                Regards,

                ~Mohit

                • 5. Re: Delete Preview File?
                  dj_paige Level 9

                  mohgoyal@adobe.com wrote:

                   

                  You can try rename the the Previews.Lrdata to Previews.Lrdata.old and open Lightroom and see how it responds.

                   

                  If it works fine with no issue you can move the Previews.Lrdate to any other drive or trash it as Lightroom regenerates it whenever you open it.

                  It works fine, except for the fact that now the LRDATA.old and the newly created .LRDATA are both on the user's SSD, taking up space, which is the issue he is trying to solve.

                   

                  Mike240: I believe you need to find out how to do a symbolic link in your operating system, there are some threads here in these forums on this subject.

                  • 6. Re: Delete Preview File?
                    mike240 Level 2

                    dj_paige wrote:

                     

                    Normally the previews need to be on the fastest disk, otherwise you may see some slowdowns in Lightroom. Nevertheless, it might still be worth a try to see if the slowdown is tolerable. There is a way to access previews via even if they are not in the same folder as the catalog itself, but I do not know the details. You can either search the forums or wait until someone who knows the details replies here.

                     

                    Simply moving the previews to another drive, without the aforementioned method of accessing the previews, doesn't really help you at all, Lightroom will just regenerate the previews on your SSD, saving you no space at all.

                    Thanks dj Paige,

                     

                    I've been searching for further fixes and have come across a method to create a symbolic link. I think that's what you were referring to. This is the download Link Shell Extension . After a bit more research I might give it a try. Thanks again.

                     

                    Mike.

                    • 7. Re: Delete Preview File?
                      ItWasNotMe Level 1

                      Why not...

                       

                      1. Delete (or rename to somewhere else) the old previews file, and create a new one

                      2. Select just the 'newer' folder, or build a smart collection that contains the images for which you want previews

                      3. Select everything in that folder/collection and 'overnight' under the Library menu item choose Build Previews

                       

                      That way you have a new previews folder, populated with the things you want visible and only get the 'Loading' message if you step outside that collection.

                       

                      NB. I think you can carry on working while the previews are being built in the background

                      • 8. Re: Delete Preview File?
                        mghbird

                        Thanks ItWasNotMe.

                         

                        Interesting work around. My thoughts had been going in a similar direction. So, thanks for the suggestion. It's rather surprising that there isn't an Adobe approved and validated solution to this that's foolproof and works without issues. I can't help feeling we are soon to get to the stage where the community of Lightroom users (who have moved through from version 1  to present) will have built up big catalogues and, corresponding large preview files. I don't think I'll be the only one wrestling with this!

                         

                        Mike

                        • 9. Re: Delete Preview File?
                          dj_paige Level 9

                          Does building new previews reduce disk space? I don't think it does, unless you also change the options about building previews so that you no longer have 1:1 previews, which then of course results in a delay for ALL photos. It's a tradeoff.

                           

                          You can't build previews on just a fraction of the photos, or the ones in a smart collection, the process builds the previews on all photos.

                          • 10. Re: Delete Preview File?
                            dj_paige Level 9

                            My solution, if you can possibly manage it, is to get a bigger SSD so there is enough space for all of your 1:1 previews and everything else you need to put on the SSD.

                            • 11. Re: Delete Preview File?
                              ItWasNotMe Level 1

                              Obviously doesn't reduce disk space if you rebuild ALL the previews.

                               

                              But when you have a selection there is a prompt to the effect that is this just for that or for all photos, so if you don't rebuild all then you save some space; but its only temporary fix as they will rebuild as and when you visit the other folders/collection and so if you visited every image you would be back to original size

                               

                              I just tried this:

                              1. Rename previews to save (previews is c71GB)

                              2. Open Lightroom

                              3. Select Smart collection with 6 photos, build previews

                              4. Resulting Preview file 10mb, not growing as I haven't moved off that smart collection

                              5. Select another smart collection (c300 photos) ; build previews; Lr scans existing previews and builds new ones as required - message is 'Built 295 previews' - not the 30,000+, that are in my library

                              6. Resulting file 256mb, not growing as I haven't visited a 3rd collection/folder

                               

                              Drawback is that any time you visit a collection/folder you may build previews for that, and so to reiterate - its only a temporary fix

                               

                              IMHO Shouldn't be a huge deal for Adobe to separate location of Catalog and Previews in the way that it does for catalog and backups.

                              • 12. Re: Delete Preview File?
                                mghbird Level 1

                                dj_paige wrote:

                                 

                                My solution, if you can possibly manage it, is to get a bigger SSD so there is enough space for all of your 1:1 previews and everything else you need to put on the

                                Thanks again dj.

                                 

                                My new PC is a bit of a beast (don't tell my wife now much I spent on it ) and the SSHD is big and fast. So, there is enough room.... It's just that it leaves me feeling uneasy that the previews have claimed 130GB of it!

                                • 13. Re: Delete Preview File?
                                  mghbird Level 1

                                  Thanks ItWasNotMe. That's good for thought. I think I need to play around with some options and see what works for me.

                                   

                                  I guess that Adobe don't separate the catalog and previews because a lot of users might be using sub-optimal computers and it would create more problems than it solves. Though an optional (non default) solution that had a health warning that made it clear that what the minimum system specs had to be, would be very welcome.

                                   

                                  Mike.

                                  • 14. Re: Delete Preview File?
                                    dj_paige Level 9

                                    Drawback is that any time you visit a collection/folder you may build previews for that, and so to reiterate - its only a temporary fix

                                    Agreed! As I said somewhere in this thread, it's a tradeoff (as is getting a big enough SSD, it solves these technical problems without tradeoff, but it's still a tradeoff with your wallet)

                                    • 15. Re: Delete Preview File?
                                      dj_paige Level 9

                                      I guess that Adobe don't separate the catalog and previews because a lot of users might be using sub-optimal computers and it would create more problems than it solves.

                                      My guess is not this. My guess is that it makes logical sense to keep the catalog and previews together as they work together; there's no reason you couldn't put the previews elsewhere on the same hard disk in terms of usability (if this was allowed in the programming, which it is not). You wouldn't want to put the previews on a slower disk (although some people do) because you take a performance hit. It really doesn't have anything to do with sub-optimal computers; the concepts are the same whether your computer is a screaming fast state of the art computer or a 5-year old clunker.