SQL 2005 move to SAN and Database Mirroring RRS feed

  • Question

  • Hi,


    We have a SQL 2005 server with database mirroring set up across a WAN.  The principal server is going to be taken down so that we can migrate storage to a SAN.  The estimated down time will be up to 8 hours.  Should we break the mirrors before we take the server down then set them back up when migration is complete, or will mirroring just pick up again after the server comes back up?



    Thursday, April 15, 2010 2:20 AM

All replies

  • Depends on how active your database is as one factor to consider is that your DB log will continue to grow during that time.


    Thursday, April 15, 2010 2:58 AM
  • Hi Ray,


    Thanks for your reply.


    When we are copying all files to the new SAN drives, SQL Server will be down, so the logs should not be growing at all, unless I am misunderstanding.


    I guess my concern is the amount of time the SQL Server service will be done, and hence should the mirror be broken first and re-established, or is there a good chance it will just pick up again after we bring the principal back up.  I prefer not to break the mirror if possible as we have many databases and would have to go through the entire process of copying full backups and t-log backups across a slow WAN line.





    Thursday, April 15, 2010 11:29 AM
  • Don't break mirroring coz you need to reconfigure it again.

    Just failover the mirroring to the mirror server, and do all the changes back in primary server and make it online then failback to the principal server from mirror, it will be synced automatically. Some of the articles for your reference



    Vidhya Sagar. Mark as Answer if it helps!
    Thursday, April 15, 2010 9:52 PM
  • Hi Vidhya,

    Thank you for the reply.

    For this move to the SAN however, we have no desire to bring the mirror up while the principal is down.  We are fine with the outage while the principal is being worked on, and we are hoping that if we do nothing mirroring wise that when we bring the principal back up it will simply reconnect to the mirror and continue where it left off.

    Does that sound reasonable to you?  If it works this way, that's all we desire to have happen.


    Thursday, April 15, 2010 11:35 PM
  • If hope there shouldnt be any problem!, it shoudl automatically synchronize. Do you configured it in High availability mode (synchronous with witness), if yes then when you shutdown primiary, it will be automaticall failovered.

    Vidhya Sagar. Mark as Answer if it helps!
    Friday, April 16, 2010 3:00 AM
  • Hi Vidhya,


    No, we have no witness and our mirroring mode is high performance due to the relatively slow WAN connection.  Our solution is more of a planned failover strategy as opposed to automatic.  We don't mind the short down time to move the SQL Server storage of the principal to the new SAN, hence, our hope would be that mirroring simply picks up where it left off after the principal comes back up on the SAN.


    Thanks again for your help

    Friday, April 16, 2010 3:31 AM