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  • Exchange database, Fix or Replace

    Hi All,

    We are having a few issues recently since our server decided to reboot itself without warning, one of which was the backup was not completing complaining about problems with accessing the exchange database and vss snapshoting.

    I attempted to run a defrag on the database which failed and the error once investigated eventually suggested corruption.

    I have found information with regards to fixing with a combination of eseutil and isinteg the former coming with a warning that where corruption has occured there will almost certainly be data loss.

    I have in the past replaced stores by removing the existing database from MDBdata folder and then restarting the IS store to generate a new one.

    What im wondering is am i better off just exmerging all the email out to .pst files , moving database and initializing new one then importing it back? I would of course scan each pst for issues before doing so.

    I understand that there are hidden elements of users mailboxes you dont see, such as out of office reply settings but in our case this should be minimal.

    What would you guys recommend, spend hours on a fix which may still not work or bite the bullet and go for database replacement.

    As it stands exchange is running and accepting new emails but I dont know how long for.

    Any advice would be great.

    Thank you.
    Ben Gillam MCP/MCSA 2003 - IT Manager (IGC Group)

  • #2
    Re: Exchange database, Fix or Replace

    Which version of Exchange - Standard or Enterprise - are you running?

    If you run EE I would simply create new databases and move the mailboxes over, if you use standard version I would consider to use a swinging server.

    You can also try to create a new database file with empty mailboxes like you already suggested and use the Recovery Storage Group mounting your original database and merge content.

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    • #3
      Re: Exchange database, Fix or Replace

      server is sbs 2003, not used a recovery storage group before, i take it that just mounts it as a secondary store, will do some more reading into that as it may be quicker than exmergeing out and back in .

      Thanks
      Ben Gillam MCP/MCSA 2003 - IT Manager (IGC Group)

      Comment


      • #4
        Re: Exchange database, Fix or Replace

        No point wasting your time scanning PST files. If there is corruption in the database then it will not come out in the PST export because it can't be read.

        Exchange database corruption is rare. If you have had to do it before then you failed to resolve the underlying cause of the issue. Therefore while you have problems now, you do need to find out why. I have Exchange 2003 system that have been going for six or seven years on their original database.

        A repair should be attempted, but be aware that anything you do to the database is not completely risk free. Data loss should be expected - even from an exmerge export.

        If the repair works, then I would consider standing up a temporary Exchange server, migrating the mailboxes to it, then dropping the database and replacing it. The mailboxes can then be moved back and the temporary server removed correctly.

        Simon.
        --
        Simon Butler
        Exchange MVP

        Blog: http://blog.sembee.co.uk/
        More Exchange Content: http://exchange.sembee.info/
        Exchange Resources List: http://exbpa.com/
        In the UK? Hire me: http://www.sembee.co.uk/

        Sembee is a registered trademark, used here with permission.

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        • #5
          Re: Exchange database, Fix or Replace

          Hi,

          Second server isnt an option unfortunately. I do not have any appropriate hardware or the licences to do it.

          The reason for eliding there is corruption that that an eseutil defag crashed out with an error which suggested corruption and I was running the eseutil was because of the backup VSS having issues with exchangen backup.

          As far as I can tell from a user perspective everyone has all of their history ok so an emerge of pst files would at least mean we have a clean copy and by replacing the database files will eliminate any problems specific to the edb.

          My fear is I could run the repair tool on the database and lose data as expected but not know what went, though I guess I could just merge the pst files back in afterwards replacing duplicates unless of course that would just reimport any corruption.

          Thanks
          Ben Gillam MCP/MCSA 2003 - IT Manager (IGC Group)

          Comment


          • #6
            Re: Exchange database, Fix or Replace

            Exchange 2003 will run on pretty much anything. You just need storage and a system with at least 1gb of RAM. My laptop could run it. Then use trial versions of Windows and Exchange to hold the database.

            If you do an exmerge out and import than you will get bloat. If your current database is being reported as say 50gb, then you could gain another 10gb because of the loss of Single Instance Storage and other efficiencies in the database.

            Simon.
            --
            Simon Butler
            Exchange MVP

            Blog: http://blog.sembee.co.uk/
            More Exchange Content: http://exchange.sembee.info/
            Exchange Resources List: http://exbpa.com/
            In the UK? Hire me: http://www.sembee.co.uk/

            Sembee is a registered trademark, used here with permission.

            Comment


            • #7
              Re: Exchange database, Fix or Replace

              hi all, just wanted to follow up on this post after the fix.

              Eventually i went down this route, posting in case it helps others.

              1) Exmerged all mailboxes to .psts as precaution and quick access if i had to go with blank database. Also backed up my edb/stm files

              2) Ran eseutil /p on the database, which ran and corrected a bunch of things, but not as bad as i had expected. Backed up database as it stood again.

              3) Ran eseutl /d on the database, this now completed and didnt bomb out with jet errors this time (the ones i got last time i tried this pointed at corruption after googling). Backed up stores again at this point.

              3) Ran isinteg servername -fix -test alltests on the store (store service needs to be running but store dismounted) - This fixed a few more issues with the database but fixed what was left.

              Finally i then ran a backup with backup exec of the exchange system which is what started this all off with very odd errors when trying to backup or access the database, this all ran fine with the exception of a missing mailbox it couldn't backup but that was my fault as i had not run the cleanup agent on a mailbox i removed and hadn't updated the backup job.

              So far it looks to be running fine now and nobody has complained of any missing mail, im going to keep the store backups for a few days then get rid and use the exmerged data if anyone pipes up about any missing messages.

              Just a shame i had to do all that over the weekend when im not supposed to be working!!
              Ben Gillam MCP/MCSA 2003 - IT Manager (IGC Group)

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