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Tanmoy1's avatar
Tanmoy1
Level 4
14 years ago

Multiplexing and Multistreaming Relation.

I need to know the relation between Multiplexing and Multistreaming setting for Netbackup.How can I determine the number of concurrent jobs for a given setting such as Multiplexing,Multistreaming,Jobs/ Policy and Jobs/Drive settings etc.Could you please let me know the same...

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  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    14 years ago

    Hi,

     

    Multistreaming relates to the client, i.e how many streams 1 client can send. This is controlled with "allow multiple datastreams" on the policy. This is also controlled in the master host properties > global attributes, "maximum jobs per client" setting, and finally you can also limit the "jobs/streams" per policy on the policy as well.

     

    Multiplexing is how many streams (from a client) can go onto a tape (or media). This is controlled on the storage unit properties (Enable Multiplexing > Maximum Streams per drive), and also setup on the schedule (media multiplexing) in a policy. The storage unit being the ultimate decider though. If you set 2 on the storage unit, and 4 in the schedule, then the jobs will use 2 drives, with 2 streams. All of this assuming you've allowed the client to send 4 streams through the settings described in the first paragraph.

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  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    Level 6
    14 years ago

    Hi,

     

    Multistreaming relates to the client, i.e how many streams 1 client can send. This is controlled with "allow multiple datastreams" on the policy. This is also controlled in the master host properties > global attributes, "maximum jobs per client" setting, and finally you can also limit the "jobs/streams" per policy on the policy as well.

     

    Multiplexing is how many streams (from a client) can go onto a tape (or media). This is controlled on the storage unit properties (Enable Multiplexing > Maximum Streams per drive), and also setup on the schedule (media multiplexing) in a policy. The storage unit being the ultimate decider though. If you set 2 on the storage unit, and 4 in the schedule, then the jobs will use 2 drives, with 2 streams. All of this assuming you've allowed the client to send 4 streams through the settings described in the first paragraph.

  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    14 years ago

    But, would make a slight amendment:

    "Multiplexing is how many streams (from a client) can go onto a tape (or media)."

    to:

    "Multiplexing is how many streams (from mulitple clients) can go onto a tape (or media)."

    or is that just me being pernickety? ;)

  • Tanmoy1's avatar
    Tanmoy1
    Level 4
    14 years ago

    Hi Riaan,

    Thanks a lot for your reply...but as per symantec glossary

    multiplexing

    The process of sending concurrent-multiple backups from one or more clients to a single storage device and interweaving those images onto the media.

    http://www.symantec.com/business/security_response/glossary/define.jsp?letter=m&word=multiplexing

     

    Also can you please answer the below question any explain....Please.... :)

    Allow Multiple Data Streams is enabled.
    ALL_LOCAL_DRIVES is specified.Media multiplexing is set to 3.
    Two tape drives are available in the storage unit and MPX per drive is 2.
    Max Jobs per Client is set to 8.
    The client has five local file systems with no exclude list.
    How many backups will be active (versus queued) after the policy is successfully invoked

  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    Level 6
    14 years ago

    Hi,

     

    This seems like an exam question....

     

    4 active 1 queued

     

    In real life there could be another job for system state if the client was windows. And of course there could be a parent job too (for BMR) but i don't know what the option are :P

  • Tanmoy1's avatar
    Tanmoy1
    Level 4
    14 years ago

    Thanks again...can u please explain in brief for my understanding... smiley  Please....

  • RiaanBadenhorst's avatar
    RiaanBadenhorst
    Level 6
    14 years ago

    Given the information in the question, and leaving real world aside.

     

    streams from the client = 5

    storage unit configuration limits jobs per tape drive / media to 2

    You have 2 drives, so 2 jobs per drive = 4 jobs that can go active.

    Max jobs per client is 8, which is higher than the number of file systems (5) on the client. It has no impact in this scenario.

    Media multiplexing on the schedule is set to 3. This is higher than the setting configured on the storage unit. The storage unit wins this battle.