Results 1 to 7 of 7
  1. #1
    Join Date
    Dec 2009
    Posts
    43

    Question Unanswered: Change OS Time - how will DB2 cope?

    Code:
    AIX 3 5
    
    DB21085I  Instance "db2inst1" uses "64" bits and DB2 code release "SQL09017"
    with level identifier "02080107". Informational tokens are "DB2 v9.1.0.7", "s090308", "U823509", and Fix Pack "7".
    Hi,

    One of our production servers time is currently two hours out.

    It hosts six small db2 databases and I would like to know if changing the time by two hours in the past is going to effect them.

    The timezone and day light savings time are both set the same as a server that is currently showing the correct time.

    I had a look at some other production db2diag.logs on other servers over the day light saving time change at the weekend and they both look fine.

    I was planning on changing the time via smitty.

    Thank you.

  2. #2
    Join Date
    Jan 2010
    Posts
    335
    You want to jump back in time? It also depends on your Application. What happens if an order was shipped before it was placed?

    Usually you can slow down the System time till you have the right time in your box, but this might take days until it's completed. You could also get a downtime for 2 hours.

    Set up a synchronisation with a time-server for your Servers.

  3. #3
    Join Date
    Dec 2009
    Posts
    43
    You are right, wanting to go backwards is problematic.

    I agree that slowing down the system time is the way to go (not smitty now). The other option did occur to me too, but it's slightly more risky as I don't know 100% what else I might effect and getting downtime for all the databases may be an issue.

    I will find out what we are doing about a time-server for these production servers.

    Thank you for all your advice.

    =======================

    Edit: made the change yesterday, AIX date command

    Aix, changed the date to lose 7080 seconds,

    date -a -7080.0

    all working ok.
    Last edited by hazy_dba; 11-02-11 at 09:17.

  4. #4
    Join Date
    Apr 2011
    Posts
    19
    DB2 could care less what time it is. I have shifted it back and forth through years during millennium testing. It is the applications that do, depending on how they are written.

    Damn I have been using DB2 over 11 years... now I am kinda depressed. Time flies I guess.

  5. #5
    Join Date
    Dec 2009
    Posts
    43
    What about timestamps for backups?

    From what you have said, I would guess that DB2 doesn't care that the string of numbers relate to a date that is possibly in the future, it just knows that it has a history of backups and these are their names?

  6. #6
    Join Date
    Apr 2011
    Posts
    19
    Yes it is just a name. Now a foll forward to a Point In Time would be the tricky part if you had shifted a great deal.

    Remember in the U.S. time shifts twice a year forward or back and no databases are affected.

  7. #7
    Join Date
    Jan 2010
    Posts
    335
    Don't know, if it's recommend, but i'm using UTC for the Hardware-Clock to cope with daylight savings time.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •