4 Replies Latest reply on Jan 13, 2016 10:34 AM by ender

    Changing one file in a multiple-file served database

    ender

      This is probably a very simple question, but I'm not finding a clear-cut answer for my situation that I fully understand: Can I make changes to a COPY of ONE file of a multi-file served database, and then upload only that file? Or does that disturb what I've read are "hard links" Filemaker creates between files when performing backups?

       

      We have:

      - a served database solution (FMS13 on Mac OS) of 18 served files, about 1.4 GB.

      - It is a legacy system updated several times (originally from FMP5, I believe).

      - We have frequent scheduled backups using FMS. We do not use Filemaker Go.

      - The database is mission critical.

       

      On my own Mac desktop, I have a copy of a backup from about a week ago.

      - I copied the complete backup folder with all 18 files.

      - I have been making extensive changes to one file of the 18 (scripts, layouts, a few new fields), and testing with existing data. (I am not using a clone, I have a copy with data.)

      - This file has some relationships to the other served files.

      - It has only one table (although in the future I will have to edit files with multiple tables.)

       

      When finished with the changes, I had planned to import current data for this file (on an evening when no one is using the database) into my changed copy, and then upload that single file to the server, (I then will have to make small online changes to two of the other served files.)

       

      Is this a safe and practical approach, or am I looking at something much more involved in order to keep all 18 files "synced" and avoid corruption?

       

      My experience with FM Server is basic setup, and a couple of times when the server crashed I served a recent backup--uploading ALL files from that backup. .

       

      Thank you.

        • 1. Re: Changing one file in a multiple-file served database
          macwombat

          Hi

          ender wrote:

           

          Can I make changes to a COPY of ONE file of a multi-file served database, and then upload only that file?

           

          Short answer - Yes you can.  But like all things you should do some careful testing to ensure that you don't have problems.  I have done this on many occasions in a multi file solution.  Things to look out for as possible issues:  the Perform Script step losing its link to the correct script from other files.  <unknown> in the predicate in relationships.  <field missing> in field definitions / calcs.

          Or does that disturb what I've read are "hard links" Filemaker creates between files when performing backups?

          Not sure about this - but I would think that as its a new file FMS will keep a copy of the new file in the subsequent backup rather than the hard link to the previous file.  Its my understanding that the "hard links" are to avoid keeping multiple copies of a file that has not changed.  Someone else may be able to provide a clearer picture of this aspect of it.

          • 2. Re: Changing one file in a multiple-file served database
            ender

            Thank you for the reply, Chris.

             

            I do plan on thorough online testing in addition to the testing I'm doing on the local copy. I'll run a backup of the entire solution immediately before uploading the new file, so if any strange behavior occurs while testing, I can restore a complete [integrated] backup.

             

            This is the section of the FMS guide that I find confusing:

            Every time a scheduled backup task runs, FileMaker Server checks whether the selected databases have changed since the last time that scheduled backup ran. For each scheduled backup task, FileMaker Server creates a full copy of the databases that have changed and creates hard links to the backed up databases that have not changed for that scheduled backup.

             

            My concern is that by uploading one altered file--with an obviously different time stamp--to the served folder (.../Library/Filemaker Server/ Data/ Databases) I would be disrupting FMS's internal tracking/linking system. My greatest concern would be the DBA's nightmare of introducing some corruption that would not immediately be evident, users would resume working, and I discover later that I have a mess on my hands.

            • 3. Re: Changing one file in a multiple-file served database
              wimdecorte

              ender wrote:

               

              This is probably a very simple question, but I'm not finding a clear-cut answer for my situation that I fully understand: Can I make changes to a COPY of ONE file of a multi-file served database, and then upload only that file? Or does that disturb what I've read are "hard links" Filemaker creates between files when performing backups?

               

              You would not be upsetting any hard links in backups since the new file would be recognized as modified and would be not-hard-linked in the next backup.

               

              You're only concern is going to be with making sure that all the internal IDs of your tables and fields and script names are still in-line.

              • 4. Re: Changing one file in a multiple-file served database
                ender

                I understand now--I realize now that I was misreading the reference to "linking" in the FMS guide. I will watch for any <unknown> / <missing> issues. I will also run through scripts again (in the uploaded files) with the debugger to verify all is working as anticipated. Thank you both for your feedback and suggestions.