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blanco_adalbert's avatar
blanco_adalbert
Level 5
11 years ago

Disable client/server host cache on netbackup

Dear All,

 

I am working on a cluster configuration for netbackup services running in two different sites (global/metro cluster).

 

1)   The issue i am facing is that each site has different ip address segment, for example, when the master active node is running on site 1 the master ip address is 1.0.0.1 furthermore when the active node change to second site the ip address is 2.0.0.1

So to identify the active ip addres for the virtual name we are using the VCS Agent for DNS in order to update the right IP on the DNS server.

 

Because the clients looks for the ip address from the DNS, they can communicate via ping but when we run bpclntcmd -hn master_server it returns the old ip address  ( ip address from passive node that was umplumbed ), so I run the bpclntcmd -clear_host_cache; after that netbackup services run well

 

Based on the enviroment my question is, are there any option to disable the netbackup host cache in order to resolve the correct ip address?

2)  When i run the switchover the media server that was active configured appear as offline mediaserver, 

 

Does any body know if the issue is regarding to the host cache?

 

 

Best Regards.

 

 

 

 

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  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    11 years ago

    Hi,

     

    Your issue is caused by PBX. PBX caches hostname entries but you can, and should clear it with

    bpclntcmd -clear_host_cache (run it a fews times and then run bpclntcmd -self).

    Then you should also do this for the media servers as their cache would still reflect the primary sites name. If you're running unix/linux and have remote execution (ssh) on all systems you could probably put it all in the preonline script.

    You should put this into a pre online script so it runs before the NetBackup starts in either site, or do it manually during switch over to the remote site.

  • Nicolai's avatar
    Nicolai
    Moderator
    11 years ago

    You can change the windows cache time in the OS

    Changing DNS Cache Settings in Windows

    http://www.tech-faq.com/how-to-flush-dns.html

  • Alfonso_Tenorio's avatar
    Alfonso_Tenorio
    11 years ago

    Hello.

    As read in technote: ( http://www.symantec.com/docs/TECH179465 )

     

    Cause

     
     

    NetBackup 7.0.1 and above cache DNS provided hostnames and IP addresses with a time-to-live (TTL) of 3600 seconds.  Depend on when the DNS IP Failover occurs, it may be up to an hour before the entry is refreshed.  Once the refresh occurs, normal NetBackup operations will resume.
     

     

    Solution

     
     

    A delay of up to an hour before resuming successful operations may be acceptable for some hosts at some sites, but not for others.  The delay can be minimized by shortening the host cache TTL on critical host.  Please review the information below carefully before proceeding

     

     

    Regads

     

  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    Level 6
    11 years ago

    Hi,

     

    Your issue is caused by PBX. PBX caches hostname entries but you can, and should clear it with

    bpclntcmd -clear_host_cache (run it a fews times and then run bpclntcmd -self).

    Then you should also do this for the media servers as their cache would still reflect the primary sites name. If you're running unix/linux and have remote execution (ssh) on all systems you could probably put it all in the preonline script.

    You should put this into a pre online script so it runs before the NetBackup starts in either site, or do it manually during switch over to the remote site.