Understanding messages about long checkpoint

  • Hi all

    Lately I've seen some messages about long checkpoints in our server. The messages look like this:

    FlushCache: cleaned up 311 bufs with 275 writes in 100497 ms (avoided 7 new dirty bufs) for db 4:0

    average throughput: 0.02 MB/sec, I/O saturation: 3139, context switches 6607

    last target outstanding: 2, avgWriteLatency 627

    I understand parts of this message. I do understand that the checkpoint had to write 311 pages and it did it by issuing 275 reads operation. This took 10004.97 seconds. The throughput was 0.02 mb/sec (kind of shocking, I think that hand writing can be quicker). What I don't understand is the other parts of this message (e.g. I/O saturation: 3139, context switches 6607 last target outstanding: 2, avgWritLatancy 627). Any explanation about this part would be greatly appreciated.

    Adi

    --------------------------------------------------------------
    To know how to ask questions and increase the chances of getting asnwers:
    http://www.sqlservercentral.com/articles/Best+Practices/61537/

    For better answers on performance questions, click on the following...
    http://www.sqlservercentral.com/articles/SQLServerCentral/66909/

Viewing 0 posts

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