Database mirroring failover error...plz help RRS feed

  • Question

  • Hi,

    I am using database mirroring with high performance(asynchronous) operating mode. When i am trying to failover i am getting the following error: "the mirror server instance is not caught up to the recent changes to database unable to failover"

    could anyone please help me out with this

    Friday, June 11, 2010 3:21 PM


  •  Hi Kiran,

    Failover between principal and mirror in database mirroring is dependent on the type of configuration being used. In a failover, the mirror server becomes the principal and the principal becomes the mirror.


    Manual Failover: This kind of failover is possible only in High Protection configuration. If mirroring is running in High Performance configuration, it has to be changed to High Protection in order to be failed over manually to mirror server.

    This can be done right-clicking on mirrored database on principal server and selecting ‘Mirroring’ tab under ‘Properties’.

    Once High Protection configuration is selected, click ‘Failover’ will initial the failover process.

     In case of High Performance configuration, if the principal server goes down, the mirror server can be brought online using restore command with ‘recovery’ option. This can also be termed as a manual failover.

     Automatic Failover: This kind of failover is possible only when mirroring is configured to run in High Availability configuration. In this configuration, a witness server is required which controls the failover between principal and mirror servers.

    Once principal server goes down, the witness server initiates the failover to mirror server and brings mirror database online for user connections.


    RajaSekhar Reddy . K

    Thursday, June 17, 2010 11:03 AM