DBCC CheckDb latch errors


  • Hi,


    we''re currently performing a dry run of migrating some large (100GB+) SQL Server 2000 databases from a SQL 2000 cluster onto a new 2005 mirrorred database pair.  The new configuration has completely separate database servers and a new dedicated SAN.


    Upon restoring our largest database we are seeing the following errors recorded in the log after setting up mirroring and then trying to run DBCC CHECKDB:


    "Unable to read and latch page (1:1323852) with latch type SH. 21(The device is not ready.) failed."


    We are currently investigating the SAN hardware logs to determine if this might be a physical issue as it would seem to indicate, however has anyone any experience of this or insight into what may cause this error?


    Thanks in advance!

    Thursday, December 06, 2007 3:50 PM

All replies

  • Was DBCC CheckDB clean on old SQL 2000 environment?  If yes, I suggest take a clean backup from SQL2000 to SQL 2005 and do the restore and try again.


    Wednesday, November 28, 2012 3:49 PM
  • I would suggest you to take a clean backup and restore it on test environment and try running dbcc checkdb

     run DBCC from the command line. Either osql or sqlcmd will do the trick. For instance:

    osql -E -Q"DBCC CHECKDB (master) WITH ALL_ERRORMSGS, NO_INFOMSGS" -oC:\outputfile.txt

    If any errors

    Take the DB into single user mode and run
    DBCC CheckDB (<database name>, REPAIR_ALLOW_DATA_LOSS)

    By runing the above command :
    It WILL lose data. A fair bit from some of currupted tables

    Note : Please perform this on test environment first .

    Please do a quick google search of paul randal articles regarding dbcc checkdb curroption issues


    Thanks,Suhas Vallala

    Thursday, November 29, 2012 6:04 AM
  • "Unable to read and latch page (1:1323852) with latch type SH. 21(The device is not ready.) failed."

    Continue your investigation from the SAN/hardware side, even taking fresh backup and restoring on new SQL 2005 may still cause the same issues as long as there are issues with the device
    Thursday, November 29, 2012 6:54 AM