Forum Discussion

sunny_NB's avatar
sunny_NB
Level 4
14 years ago

NEW STREAM concept

Can anyone tell me what does NEW STREAM defined in the backup selection list does when we backup unix and windows client?

7.1.x and Earlier
Backup and Recovery
NetBackup
  • Andy_Welburn's avatar
    Andy_Welburn
    14 years ago

    as I found to my cost, is for NDMP backups.

    Whilst running NB5.1MPx the backup selection for our NDMP backups were thus:

    /vol/vol1/A
    /vol/vol1/B
    /vol/vol1/C

    Now with multiple data streams enabled on the policy this resulted in 3 separate jobs (& no parent process if I remember correctly). Now each could be dealt with as a separate job & cancelled with no impact on the others.

    Following upgrade to NB6.5, the policy was not amended & what we found was that if we cancelled any of these job streams (queued or otherwise) then ALL jobs for that policy would get cancelled (again queued or otherwise) which was not good if an active stream was nearly complete at 1Tb for example!!

    We were advised that the correct way to set up this particular policy was to introduce the NEW_STREAM directive thus:

    NEW_STREAM
    /vol/vol1/A
    NEW_STREAM
    /vol/vol1/B
    NEW_STREAM
    /vol/vol1/C

    ***EDIT -  which meant that any job could be cancelled without any effect on any other currently running jobs from the same schedule - end of EDIT***

    Now I'm not sure if this was just an issue with the 6.5 release, or 6.5 in general, but all my multiple data stream NDMP backups since then have had the NEW_STREAM directive implemented.

  • Andy_Welburn's avatar
    Andy_Welburn
    Level 6
    14 years ago

    as I found to my cost, is for NDMP backups.

    Whilst running NB5.1MPx the backup selection for our NDMP backups were thus:

    /vol/vol1/A
    /vol/vol1/B
    /vol/vol1/C

    Now with multiple data streams enabled on the policy this resulted in 3 separate jobs (& no parent process if I remember correctly). Now each could be dealt with as a separate job & cancelled with no impact on the others.

    Following upgrade to NB6.5, the policy was not amended & what we found was that if we cancelled any of these job streams (queued or otherwise) then ALL jobs for that policy would get cancelled (again queued or otherwise) which was not good if an active stream was nearly complete at 1Tb for example!!

    We were advised that the correct way to set up this particular policy was to introduce the NEW_STREAM directive thus:

    NEW_STREAM
    /vol/vol1/A
    NEW_STREAM
    /vol/vol1/B
    NEW_STREAM
    /vol/vol1/C

    ***EDIT -  which meant that any job could be cancelled without any effect on any other currently running jobs from the same schedule - end of EDIT***

    Now I'm not sure if this was just an issue with the 6.5 release, or 6.5 in general, but all my multiple data stream NDMP backups since then have had the NEW_STREAM directive implemented.

  • sunny_NB's avatar
    sunny_NB
    Level 4
    14 years ago

    and how is it different when we seperate the like C : D : and so on in backup selection list. 

    or in unix when we give differant  mount points like /var , /usr etc

  • Marianne's avatar
    Marianne
    Level 6
    14 years ago

    In support of the above excellent post, just my 2c:

    If you have Allow Multiple streams selected in policy attributes, the follwing File selection:

    /
    /var
    /opt
    /usr

    Will generate a separate backup stream for each of the file systems listed above, EXACTLY the same result as:

    NEW_STREAM
    /
    NEW_STREAM
    /var
    NEW_STREAM
    /opt
    NEW_STREAM
    /usr

     

    The only place where there is real value in using NEW_STREAM is when you want to group a list in a single stream, e.g:

    NEW_STREAM
    /
    /var
    /opt
    /usr
    NEW_STREAM
    /data1
    /data2
    NEW_STREAM
    /data3
    /data4
    NEW_STREAM
    /data5
     

    The above use of NEW_STREAM will result in 4 streams being generated:

    Stream 1 will backup /, /var, /opt, /usr sequentially in one stream, /data1 and /data2 sequentially in another stream, etc...

    As per the above post - all of this is explained in detail in Admin Guide 1.