Database Mirroring Question

  • Hi everyone,

    I have successfully set up mirroring between two databases. Is it possible to remove mirroring, bring up the mirrored database and see if the changes were mirrored correctly? And is it possible to set up mirroring the way it was before after we are done? Thanks in advance for your help.

  • OK, found the Failover button in the Mirroring window. 😀 It seems to be the best way to accomplish what we want.

    Is it possible to look at the data in the mirrored database without having to go through this process? We just want to once in a while make sure that the mirroring is working fine.

  • create a snapshot of the mirrored database, then you'll have a point in time read only copy you can check.

    see database snapshots in BOL

    ---------------------------------------------------------------------

  • That's great, thanks for the hint!

  • Hi everyone,

    I am reading how database mirroring works in SQL Server TechCenter and I am having a problem with this paragraph, specifically, the bold parts:

    "To store the copied original pages, the snapshot uses one or more sparse files. Initially, a sparse file is an essentially empty file that contains no user data and has not yet been allocated disk space for user data. As more and more pages are updated in the source database, the size of the file grows. When a snapshot is taken, the sparse file takes up little disk space. As the database is updated over time, however, a sparse file can grow into a very large file."

    Isn't a snapshot supposed to take the data that is in my database and copy it to the snapshot?

  • No. Pages are only copied from the source database to the snapshot as they are changed (the pre-change information is copied). Reads from any pages that don't exist in the snapshot are forwarded to the source database. This guarantees that the snapshot will always reflect the data at the time the snapshot was created (much as a full backup would) but it's extremely quick to create.

Viewing 6 posts - 1 through 5 (of 5 total)

You must be logged in to reply to this topic. Login to reply