Forum Discussion

Arun_K's avatar
Arun_K
Level 6
13 years ago

scan hosts

 

How the scan host is determined

EMM determines scan hosts; a scan host may be different for each shared drive. The first host in the environment to come online with a non-zero scan ability factor is the initial scan host for its drives.

To configure the scan ability factor of media servers, use thenbemmcmd command. For more information, seeNetBackup Commands Reference Guide.)
  1. scan ability factor is 2.Then will this hamper anything?
  2. scan ability factor is 0.What this means?
  3.  scan host are my media servers?
7.1.x and Earlier
Backup and Recovery
NetBackup
  • mph999's avatar
    mph999
    13 years ago

    no they will work fine.

    just because a drive is down does not mean it is anything to do with the scan host.

    it is an impossible question "what if " I don;t know, it hasn't happened.

    NBU is too complex to guess at things that have not happened.

    That is my final answer on this subjust.

    Sorry, but Chris Zimmerman (more important than me) wants to put a stop to these 'what if' questions - this is not what the forum is for.

    The occassion question is fine, but not multiple "what if questions" in the same day.  The answers are all out there in the manuals, you just have to spend some time loking.

    Martin

     

     

     

  • Marianne's avatar
    Marianne
    Level 6
    13 years ago

    Please show us output of 'vmdareq' on your master server.

    It is easier to explain when we compare info in the manual with output in your environment.

    The media server with highest 'scan ability' value will be the preferred scan host. 
    Each drive will have one SCAN host.

    The media server that is started first is normally the SCAN host for all shared drives.

    'scan ability' of 0 means you don't want that particular host to be the scan host for any of the drives.
    The default value is 5 on all media servers. 

    Your extract from the manual says exactly that:

    The first host (media server) in the environment to come online (started first) with a non-zero (higher than 0) scan ability factor is the initial scan host for its drives.

    (Rest of the section in SSO manual is also very useful...)

     

  • Arun_K's avatar
    Arun_K
    Level 6
    13 years ago

    The media server with highest 'scan ability' value will be the preferred scan host.

     

    What will hapeen in this case.

    i have 3 media servers and 10 drives.All are shared.What this means in case of SCAN host.

  • mph999's avatar
    mph999
    Level 6
    13 years ago

    Type.

    "netbackup scan host" into google, top answer is :

    http://www.symantec.com/docs/HOWTO32788

    "The media server with highest 'scan ability' value will be the preferred scan host.

    What will hapeen in this case.

    i have 3 media servers and 10 drives.All are shared.What this means in case of SCAN host."

     

    We are not getting into 'what/ if' questions - is there actually an issue ?, if not, leave things alone and do not change settings.

    Everything you need to know about scan host is in the link I mentioned.

    If things are runnign and you have no issues, theer is no problem.  If you do have a real problem, then let us know.

    On a system your size, the default settings should be fine, or what every yours settings are fine if things are working.

  • Marianne's avatar
    Marianne
    Level 6
    13 years ago

    Please read through my previous post again. 

    I promise you - the answer is there. Really.

    Please also post output of vmdareq command.
    This will show us how the theory in the manual is applied in YOUR environment.

  • mph999's avatar
    mph999
    Level 6
    13 years ago

    Exactly what it says. - Read it again the answer is there.

  • Arun_K's avatar
    Arun_K
    Level 6
    13 years ago

    The media server with highest 'scan ability' value will be the preferred scan host. 
    Each drive will have one SCAN host.

     

    What abt the other media servers with low scan factor?

  • Marianne's avatar
    Marianne
    Level 6
    13 years ago

    Nothing.

    Question already answered.

    3rd request:

    Please post 'vmdareq' output.
    This will show you 'what about' other media servers.

     

  • mph999's avatar
    mph999
    Level 6
    13 years ago

    If the media server with the highest scan ability  value is the preferred one, what do you think this means about the others ...

     

  • Marianne's avatar
    Marianne
    Level 6
    13 years ago

    If you had a REAL environment, you would know that this is NOT the case.
    Is that why you keep on ignoring my request for vmdareq output?
    Just another theoretical question?

    If you read further in the manual (as per my suggestion above) you will see what the real purpose of a Scan Host is. See: Shared tape drive polling.