3 Replies Latest reply on Oct 28, 2014 3:16 AM by areohbee

    can i erase lightroom files cache00000.dat?


      am traveling and using 1G Lacie Thunderbolt portable drive to store photos. Drive is full - strange...but lots of memory is using LR files labeled cache000000.dat (different sets of zeros, this just an example). I think I started to use LR on my MacBook to start new catalog a few days ago...but there are only five photos there...and really I just need to save everything on the road and do post processing at home on MacPro. Don't want to have to buy another external drive tonight...these files all look like trash to me - they are dated the past few days so not anything older where I'd lose the LR connection. I've been using Nikon ViewNX2 to transfer from camera's compact flash to the Lacie external. Figured all photos could live there and I can work them at home. But afraid to erase these cache00000.dat files until I"m sure it's ok. Thanks for any help you might offer!

        • 1. Re: can i erase lightroom files cache00000.dat?
          areohbee Level 6

          Those are develop-edit cache entries.


          Consider purging your Camera Raw cache, and/or reducing it's maximum size (see Lr preferences).



          • 2. Re: can i erase lightroom files cache00000.dat?
            gunsue Level 1

            Thank you so much, Rob! I have all images already on the MacPro with LR - thinking I could just delete these cache files as I still have the images separately

            • 3. Re: can i erase lightroom files cache00000.dat?
              areohbee Level 6

              You're welcome gunsue.


              If ACR/Lr not running, you can delete the entire contents of the folder containing the .dat files, assuming that folder is indeed the ACR cache folder - you should also see an Index.dat file, and NO other files (besides the Cache00000001234.dat files I mean). That is exactly what happens when you click the Purge Cache button in Lightroom's preferences dialog - it deletes the contents of said folder. But note: it's contents will be regenerated as you use the software again, BUT today's entries are smaller than yesterday's (assuming you are using Lr4 or Lr5), so it won't take as much space as it would, or did (and maybe still is), from when you had Lr3, 2, or 1.


              Anyway, consider putting a 5 or 10 GB (or less) cap on it (maximum size) to be sure it doesn't take too much room in the future.


              Note: you can simply make the folder non-writable if you are really pressed for space and ACR/Lr will simply not create cache entries at all. That will adversely affect performance, but only a tiny bit (a surprisingly small amount, like a small fraction of a second when loading a photo for develop).