5 Replies Latest reply on Nov 29, 2015 3:42 PM by ssprengel

    Can H U G E Lightroom Media Cache Files Be Deleted

    Mel Hughes Level 1

      Hi everybody,

      I really need some help from experts!!


      I have about run out of space on my 256 GB SSD boot drive.  It seemed impossible so I started checking and found that there is a Media Cache File that is 104 GB.  This file is located at: C:/Users/me/APPData/Local/Adobe/Lightroom/Caches/Video/Media Cache Files.  When I look at the files themselves, the VAST majority are associated with videos I have downloaded from the Creative Live website for photography, Lightroom and Photoshop training I have purchased.  These mp4 videos are stored on a second 512GB SSD I have in my computer.  Note: I also opened Lightroom preferences and under File Handling.  I know there are 2 caches there (for Camera Raw and Videos) but they are limited to 1 and 3 GB.  I believe these files are created by Lightroom as needed in its operation.  I have purged them after learning Lightroom will recreate them as required but STILL have this huge amount od data in the Media Cache File.


      The confusion I have is that these mp4 videos talk about LR and PS but to my knowledge do NOT interface directly with LR or PS in any way.  They are standalone videos that do NOT cause LR or PS to open or operate.


      So, my questions are:

      1.  General curiosity as to why 104GB of files were created in the first place that appear to be in addition to the actual mp4 videos themselves


      2.  If I delete these video cache files, will the mp4 videos still run?  It took a huge amount of time to download all of these videos onto my hard drive and I would like to not have to spend those hours again.


      3.  If it is OK to delete these files, how best to do it?  Can I simply highlight the files and drag them into the Trash.



      Thanks for the help.  I really need to recover space on my boot drive and do not understand what is going on.  I might point out that my computer has 16GB of RAM




        • 1. Re: Can H U G E Lightroom Media Cache Files Be Deleted
          Just Shoot Me Adobe Community Professional

          Yes. This is a BUG. As Adobe hasn't enabled a way to limit the Video cache size.

          • 2. Re: Can H U G E Lightroom Media Cache Files Be Deleted
            Mel Hughes Level 1

            Why did LR create such huge media cache files when I copied mp4 video files that have NOTHING to do with LR?

            • 3. Re: Can H U G E Lightroom Media Cache Files Be Deleted
              Just Shoot Me Adobe Community Professional

              Did you import them into LR. I recently accidentally clicked on a folder that has old Batman TV videos in it while I was in the LR import dialog and after reading your original post went to the folder you listed and found 35+ GBs of files in that cache folder. Seriously I just Clicked on that folder then off of it not 5 seconds later and LR created 35+GBs of cache files.


              What version of LR are you using? If it is still the 2015.2.x/6.2.x version and you get that lousy start screen to the import window that SEARCHES all your drives looking for images to import. That could be the cause.

              • 4. Re: Can H U G E Lightroom Media Cache Files Be Deleted
                Mel Hughes Level 1

                I am using LR CC.


                I just opened the files on the Creative Live website, selected Save As and downloaded to a Photography Training folder on the secondary SSD I have.  It NEVER involved LR from my end as far as I know.  Certainly nothing overt on my end.


                I did just go to LR Preferences and clicked on the purge button for the Camera Raw and Video cache (supposedly limited to 1 and 3 GB, respectively) and lo-and-behold, ALL 104 GB in the offending Media Cache File was erased.  And happily, the mp4 videos STILL work.


                So, looks like the acute problem is solved BUT I would still like to understand why LR felt obliged to create 104GB of files for downloaded training that had nothing to do with LR.


                I am confused

                • 5. Re: Can H U G E Lightroom Media Cache Files Be Deleted
                  ssprengel Adobe Community Professional & MVP

                  LR tells a separate process to scan for and create cache files from each video file in folders you click on to navigate where you want to import from, or maybe, now, from drives you import from.  This process, once started, it independent of LR, so shutting off LR has no effect.  Theoretically, if LR were to import those files, then it wouldn't need to build the cache, because the cache is already built for them during the prescan, but because the cache as built by the independent process, it doesn't know if LR is actually importing videos from the folders you've clicked on getting to the folder you're importing from, much too many videos are scanned and cached.


                  I was thinking that Adobe changed something in how LR 6.3/2015.3 works so it wouldn't do this scan so imprecisely but I haven't verified what this latest update still does, so I'm not sure if it's been fixed, or not.


                  Verify that the most recent LR 6.3/2015.3 update is still causing a problem and that your cache hasn't been filled up with caching from previous versions of LR before you go renaming the exe.


                  The dynamiclinkmediaserver.exe is the name of the process, and using Task Manager you can find where this exe files resides on the hard-disk and rename it if you want to stop the behavior from occurring, at least until the next Adobe product is installed, which will likely put it back.