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  • 1.  NTP information on AIX

    Posted Tue May 18, 2021 09:51 AM
    Hello All,

    I have query regarding NTP in AIX. In my environment we have made AIX lpar as NTP server and rest of lpars as the clients. So now if I increase the NTP server time by 1 minute will it impact the clients which are running application and DB. I

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    Rohit Rohit
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  • 2.  RE: NTP information on AIX

    Posted Wed May 19, 2021 10:47 AM
    Hi Rohit,

    From NTP perspective, if you change the server time by 1 minute, all the clients also would change their time by 1 minute in a step. This would happen after some time. I cannot tell how the applications or the DB's would react to this sudden change in time. It's better you check the respective documentations/vendors on whether this is something that you can do without any issues.

    Regards,
    Srinivas.

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    SRINIVAS GUNDURAO
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    Original Message


  • 3.  RE: NTP information on AIX

    Posted Wed May 19, 2021 10:54 AM
    Hi Rohit,

    When you change the NTP server time by 1 minute, all the clients also would change their time by 1 minute. This doesn't happen immediately, but after some time.  Not sure how this sudden change in time affects the applications and DBs that you are running. Please check the respective documentations/vendors to see if there can be any problems.

    Regards,
    Srinivas.

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    SRINIVAS GUNDURAO
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    Original Message


  • 4.  RE: NTP information on AIX

    Posted Wed May 19, 2021 11:05 AM
    Thanks Srinivas, for the reply. 

    I have already raised the query with application and DB people, they are checking at their end. Meanwhile I was just checking if any body did such changes in their environment or faced any challenges while doing so. Just giving more clarification about my environment, we have in our environment PowerHA and GPFS as well. 

    Regards
    Rohit

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    Rohit Rohit
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    Original Message


  • 5.  RE: NTP information on AIX

    Posted Wed May 19, 2021 11:05 AM
    > I have query regarding NTP in AIX. In my environment we have made
    > AIX lpar as NTP server and rest of lpars as the clients. So now if I
    > increase the NTP server time by 1 minute will it impact the clients
    > which are running application and DB.

    Yes, the clients should update to follow the server.

    Make sure you're slewing your time, not stepping your time on the
    clients. Slewing slows or speeds up the clock until it matches the
    remote server. That is safe for databases. Stepping the clock is what
    happens when the server instantly changes to the new time. That could
    go forward or backward and damage time sensitive transactions.

    In /etc/ntp.conf add a line "slewalways yes".

    Also be aware that AIX's NTP daemon will refuse to sync a time
    different greater than 1000 seconds. This protects the client from
    following an invalid server (ie: clock reverted to 1970).

    https://www.ibm.com/support/pages/node/885931


    Original Message


  • 6.  RE: NTP information on AIX

    Posted Wed May 19, 2021 11:23 AM
    Hello Russell,

    Thanks for the reply. I have already gone through the link earlier.
    Seems to be  "slewalways yes" can do the work. Can I get some more information about this option.


    Regards



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    Rohit Rohit
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    Original Message


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