Post reply

Backups

  • October 31, 2009 at 8:57 pm

    #213070

    Hi,

    How to verfiy / double cross check there is a LSN chain break?

    Is there any system table?

    Also,What is the difference between First LSN, Last LSN, Differentail LSN and Checkpoint LSN. How to analyze/understand or How these are going to help us in backup and recovery??

    Thanks in advance.

  • November 1, 2009 at 3:19 am

    #1073568

    Try BoL.

    use msdb

    go

    select*

    fromdbo.backupset

  • November 1, 2009 at 10:07 am

    #1073599

    These don't help you in backup recovery.

    The LSNs are the sequences of transactions. In ordr to restore you need the logs in sequence for there to be a chain of data you can restore. If you are missing a log file, then you cannot restore past the last point that you have.

    Think of a number line. You have a log backups from 1 to 100. If you have all 100, then you can restore from the time of item 1 to the time of item 100. If you missing 45, then you can only restore to 44. It doesn't matter if you have 46-99, if you don't have the sequence in order, you cannot move past that point.

    You are asking lots of questions that are either for research, or they are test/interview questions. Please read about these topics in Books Online, and then ask questions about what you don't understand.

  • November 1, 2009 at 1:32 pm

    #1073621

    Thanks!

Viewing 4 posts - 1 through 3 (of 3 total)

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