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Upgrading mirrored databases RRS feed

  • Question

  • I am in the process of architecting SQL 2005 HA options and of course mirroring is at the top of the list. Does anybody know what the requirements are regarding upgrading mirrored databases, for example, applying hotfixes and service packs? Is it a requirement for the principal and mirror (and witness if applicable) to be at the same build level? Is there any requirement to upgrade one first and then the other as there is with replication topologies?

    I had a look in BOL but can't find anything covering this (perhaps I missed it).

    Thx, Simon.

    Monday, April 24, 2006 12:55 PM

Answers

  • I'll start putting information about "rolling upgrades" into BOL for SP2. Since RTM did not support DBM, there was no upgrade path.

    Basically, we are doing our best so that you can upgrade the mirror, fialover, upgrade the new mirror and then fail back for minimal downtime. No promises though. I don't know what will change in the future.

    Several internal users installed patches and the Service Pack like this with minimal downtime.

    Thanks,

    Mark

    Monday, April 24, 2006 9:53 PM

All replies

  • I upgraded my servers to SP1 last week.  My config is:

    Principal: 2005 Standard
    Mirror: 2005 Standard
    Witness: 2005 Express

    All were configured initially as pre-SP1 (and pre Express SP1) with database mirroring on two databases.

    My process was upgrade Principal to SP1, then Mirror to SP1 followed by a complete reinstall of the Express SP1 on my witness box.  I did that because I messed up the initial Express SP1 upgrade because I 'hid advanced config options' which lets you choose to put it on as default instance or a named instance and ended up with a different instance that I didn't want.

    It all worked fine, and the mirroring works a little more smoothly now too.  Before SP1 I had some issues with the databases not resynchronising after a service restart.

    Ed

    Monday, April 24, 2006 5:02 PM
  • I'll start putting information about "rolling upgrades" into BOL for SP2. Since RTM did not support DBM, there was no upgrade path.

    Basically, we are doing our best so that you can upgrade the mirror, fialover, upgrade the new mirror and then fail back for minimal downtime. No promises though. I don't know what will change in the future.

    Several internal users installed patches and the Service Pack like this with minimal downtime.

    Thanks,

    Mark

    Monday, April 24, 2006 9:53 PM
  • Thanks Ed,

    useful to know.

    Tuesday, April 25, 2006 9:02 AM
  • Thanks Mark,

    obviously minimal downtime here is what we are after and being able to upgrade the mirror and then failover would be fantastic.

    Being able to plan for the next upgrade cycle and for any critical patch updates is important for us. If I'm to be able to recommend and deploy mirroring I need to have the process for this in place before deployment into production.

    thx, Simon.

    Tuesday, April 25, 2006 9:09 AM