6 Replies Latest reply on Dec 29, 2009 10:17 AM by philmodjunk

    File corruption problem - recovery

    user14360

      Title

      File corruption problem - recovery

      Post

      Hi,

       

      A database I have been working on (hosted on a Filemaker Pro 10 Advanced server, Mac, and I work on Filemaker Pro 10 Advanced on a Mac) , recently crashed and said 'this file has a problem' (or something like that), 'please use the recover function'.  (The database is 8.5MB and has 27 tables.)

       

      Some history: 

      Last week the server got shut down accidentally by someone pulling the power plug out.  It started up again ok and the file seemed to be working fine.

      Then I needed to take the database to work on it offline, so I backed it up via the server schedule, then copied the backup file to a usb, which I then emailed to myself to use on my computer away.

       

      This is the file that has now crashed (not the one on the server, although I don't know what state that is in because I haven't worked on it recently).  I tried the recovery function, and when it was finished, it said that there is something seriously wrong with the file and this recovered file should NOT be used going forwards.

        

      I have a few questions:

      1) What am I looking for in the log file to help me work out what the actual problem is? 

      2) I did a recovery of a previous version of the file (one that wouldn't have been affected by the server shut down) to see what the recovery process says.  It had the same error message at the end and said not to use that recovered file going forwards.  Does this mean that the file problem likely goes back to before the server shut down?

      3)Given that I hadn't been having problems with the file before transferring it to my computer locally, is it reasonable to assume that the file on the server is ok and to continue working on that?

      4) Are there any other tools I can use to test a file or gauge the severity of a problem?

       

      Worst case scenario is I'm going to have to rebuild the database from scratch.   This would be very painful, but not the end of the world.

       

      If I can avoid it, I'd like to, but if sticking with this file is going to create problems down the road, then it'd be better to recreate it. 

       

      Anyone's thoughts on this or experiences they can share that might help would be great.

        • 1. Re: File corruption problem - recovery
          philmodjunk
            

          When setting up a backup schedule, you should set this up so that a sequence of back up copies are maintained. My servers save 28 days of daily backups to the hard drive and then I move one copy to a monthly backup folder on the first of each month. With such a  backup series, you can then work back in time until you find a copy that is not corrupted. Using that copy, you can then import data from your recovered file to get back in operation.

           

          If you don't have such a back up series, and haven't saved a "clean clone" of the file (also a good idea). Your next best option is to rebuild the file. :smileysad:

           

          You can likely save some work by importing tables and scripts, and then copying/pasting layouts from the recovered file into your rebuilt file though you'll want to use recover periodically to make sure you aren't importing trouble into your database while you are rebuilding.

          • 2. Re: File corruption problem - recovery
            davidanders
              

            When I am creating a database, I Save As "mydb02" and "mydb03" on a regular basis.

            Always opening the latest saved as version to continue.

             

            Having a known good backup of the database is very important.

             

            Recovering a recovered ffile can sometimes fix the inconsistancies.

            Saving as Clone and Recovering the clone can sometimes fix the inconsistancies.

            Recovering on a different platform OSX or Windows can sometimes fix the inconsistancies.

             

            Font or Font Cache Corruption can be a major problem that remains hidden by focusing on the database and not underlying functions.

            Plugin Corruption and incompatiblity can be hidden by focusing on the the database.

             

            Hard Drive corruption, file transmission errors can also be ignored by focus.

             

            The backup suggestions by PhilModJunk above are very valuable. 

            • 3. Re: File corruption problem - recovery
              user14360
                

              Thanks for the responses Phil and David.

               

              I just created a copy of the file, and deleted two of the tables (called Placements and Placements Data), because the file had been crashing more frequently when I was dealing with those fields.

               

              I recovered the file with those tables deleted, and it's saying it recovered without problems: "Recover built a new database without detecting any problems.  It would be safest to copy only the most recent work from the recovered file into a backup copy of the original file, instead of using the recovered file going forward." 

               

              I'm assuming this is good news.

               

              However, the corruption in the file and my backups goes right back to a couple of months ago, so copying the newest work from this recovered file into a backup file is not ideal. (Yes, I've learnt my lesson.  I will be taking on your suggestions as to a more rigorous back-up procedure.)

               

              Do you think it would be safe to continue on with the recovered file and just rebuild the tables I deleted?  Or would you recommend starting over?

               

              If you recommend continuing on with the recovered file, would I need to rebuild the layouts that the Placements tables were using, or can I just relink the fields up with the new Placements table I create?  I only removed the tables from the file when it recovered ok, not the layouts as well, so this seems to suggest the layouts themselves are ok.

               

              This is my first experience with this, so I'm sorry for the many questions. 

              • 4. Re: File corruption problem - recovery
                philmodjunk
                  

                It's a matter of risk vs. benefit. Recover can't fix every problem so you don't know for sure that there are no problems here just that the recover didn't find any. So if you want to be absolutely sure, you'd rebuild from scratch.

                 

                However, given the amount of work that entails, it's not an unreasonable risk (in my opinion), to use your file that reports "no problems found" and rebuild the parts you deleted piece by piece.

                • 5. Re: File corruption problem - recovery
                  user14360
                    

                  Thanks to both of you.  I'm continuing on with the recovered file and hoping for the best.

                   

                  • 6. Re: File corruption problem - recovery
                    philmodjunk
                      

                    My recommendation was NOT to use the recovered file. I understood that you deleted several parts from you Unrecovered copy and got "no problems" when you recovered that file. I'm recommending that you take that unrecovered file and rebuild the deleted elements.

                     

                    A "recovered" file can contain hidden issues that aren't immediately obvious and you may not discover the issue until you encounter a disaster several days and/or many backup copies in the future.