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Hooray888's avatar
Hooray888
Level 3
5 years ago

After change the client hostname, the client backups are still working fine with old hostname

Hello Guys,

Today I made one testing --- change one NBU8.2 Linux client hostname. And then observe the client backups status.

This NBU8.2 Linux client backups always work fine before change the IP address.  Then I started to manually change the client hostname with command: hostnamectl set-hostname <NEW hostname>.  It works. Running hostname command shows the New hostname.

And I manually updated the local /etc/hosts file with the New client hostname. Then I updated the "CLIENT_NAME" entry with the New client hostname in the /usr/openv/netbackup/bp.conf file on this client. After done, I manually restarted the NBU8.2 client services on this client. All looked fine so far.   Run command: bpclntcmd -pn -verbose on this client, the output is the OLD hostname entry.

NOTE:  From NBU8.2 Master/Media servers' side, nothing is updated/changed regarding this client for now.

At this time I manually initiated the FS backup policy of this client from NBU8.2 Master side. Certainly the existing policy still contains the OLD client hostname under Client tab. As a result, the backup still worked fine with OLD client hostname.  Why? 

On the Master/Media server, run command: bptestbpcd -client <Client IP or Old hostname> , it was OK. 

I was confused.  I thought that it should be failed at the moment.  At least it needs to renew the existing certificate. Right?

Thanks in advance. 

  • sdo's avatar
    sdo
    5 years ago

    Hi - the fact that client name change does not break certification must be by design.  With certification when clients are initially installed they select (self-create and self-assign) for themselves a "host GUID".  And it is this "host GUID" which is certificated, not a client name.  Hence clients still work after changing name.

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  • sdo's avatar
    sdo
    Moderator
    5 years ago

    All NetBackup entities, i.e. Master or Media or Client, all maintain their own private cache of names and IPs in case DNS goes AWOL.  So, when changing names of anything, then you always need to execute this command, and usually it is best to execute this command on all three layers, i.e Master, all Medias and Appliances, and on the client itself:

    bpclntcmd -clear_host_cache

     

    • Hooray888's avatar
      Hooray888
      Level 3
      5 years ago

      Hi sdo 

      Thanks for your reply first.  Yes, I executed the following command on the Master, Media servers and client. 

      bpclntcmd -clear_host_cache

       

      Consequently, the backups still worked fine on the Master system.  I am confused that the backups should have failed without renewing the certificate after change the hostname of the client. 

      • sdo's avatar
        sdo
        Moderator
        5 years ago

        Hi - the fact that client name change does not break certification must be by design.  With certification when clients are initially installed they select (self-create and self-assign) for themselves a "host GUID".  And it is this "host GUID" which is certificated, not a client name.  Hence clients still work after changing name.