SQL Server Performance

(Semi-)Seamless Migration Ideas

Discussion in 'SQL Server 2008 General DBA Questions' started by dTos, Apr 7, 2009.

  1. dTos New Member

    Hey all,
    First of all thanks in advance for the help.
    What I am looking for is any suggestions for migrating a production SQL server to new hardware as seamlessly as possible.
    Basically, we've grown so much in the past year and have noted some performance issue increases relating mainly to disk (Avg. Queue Len=~7 per phys disk, % Disk Time=1500%), and we're going to upgrade to a faster disk subsystem (and new servers at the same time). The DB & Log files are currently sitting on separate RAID 1 configs. Would likely move to RAID-10 on the new system for improved writes...
    Here are the constraints:
    1. 24/7/365 shop.
    2. This machine handles ALL writes. (5 or 6 replication subsriber machines handling reads).
    3. Current machine is not in any sort of cluster. (and is SQL 2005)
    4. New machines will be clustered and must use the current machine's IP as their virtual IP. Prefer to upgrade to 2008 at the same time.
    5. 'Downtime' is not a good word.
    We could do this migration fairly easily by bringing everything down for a day/few hours, but ideally we'd like 0 downtime because of the revenue loss this will entail. If anyone has any creative ideas for keeping the downtime to a bare minimum, while maintaining system integrity, I'm all ears.
  2. melvinlusk Member

    It sounds like you're going to have to deal with some downtime to get this upgraded.
    Once you get the new hardware, go ahead and get that installed using a different IP and NetBIOS name. Install SQL on it, too.
    Are the DB's and Logs on external storage (SAN/SCSI)? If so, you could shut down the old box, rename the new one, and then present the external storage to the new box. If this isn't the case, then detach/attach is probably you're best bet for moving the data to the new box.
    Wish I could give you more advice but it sounds like you have your work cut out for you!
  3. dTos New Member

    Thanks melvin, more concerned about the migration of storage (FC SAN to new FC SAN). This is what is likely to take the largest amount of time to copy over. I'm just curious if there is any mirroring or replication tricks one can do to ease this transition...DT
  4. satya Moderator

    Have you gone through the vendor related SAN replication tools in this case?

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