Mirroring without witness and Server reboot


  • Hello all,

    I've a 2 server SQL 2008 R2 mirroring setup with multiple databases mirrored. One of the databases is big in size (200 GB). The mirroring is setup with high safety without automatic failover. In one of the environment we faced issue when both the servers were rebooted simultaneously because the database or transaction logs were not backed up and they grew huge. The principal and mirror partners went into In-Recovery mode and stayed like that for huge amount of time. Since it was not production, we broke the mirroring.

    I want to know how to tackle this in prod setup. We have daily full backups of databases and transaction log backups happen hourly. What is the nornal mode of operation for maintenance activities like patching etc? I was told that we should reboot mirror partner first and then principal. Since its high safely, the transactions should get written to both the servers. if we reboot mirror first and then the principal (BTW users are ok with 10 mins of downtime in night)  will that take care of everything? Is there any other recommendation around this? What is the ideal size of the log file so that the mirroring sunchronization happens seamless post reboot?

    Any help/pointers in this regards are highly appreciated.


    Tuesday, July 12, 2011 11:13 PM


All replies

  • Hi Mahesh,

    You are in right direction.

    Patching in mirrod environment ..

    Apply the service pack to the mirror server first
    Reboot Mirror Server
    Failover the principle databases over to the mirror server
    Apply the service pack to the former principle server (now a mirror)
    Fail the mirrored databases back to the former principle server (optional)

    200 GB is not a very huge databse,but try to decrease your log backup intervals.It will give better control on log file maintenance.

    Hope you got the idea.



    Sivaprasad.L Together We can Achieve
    Tuesday, July 12, 2011 11:54 PM
    Best Regards, Uri Dimant SQL Server MVP
    • Proposed as answer by PrinceLucifer Wednesday, July 13, 2011 7:58 AM
    • Marked as answer by Stephanie Lv Tuesday, July 19, 2011 9:43 AM
    Wednesday, July 13, 2011 6:47 AM