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yilkilicaslan's avatar
yilkilicaslan
Level 4
12 years ago

number of data buffers and size for LTO6 drives

What is the best numbers of number of data buffers and size for LTO6 drives? And which paramaters do i have to tune for best performance?

7.5
Backup and Recovery
Linux
NetBackup
  • mph999's avatar
    mph999
    12 years ago

    Try

        echo "262144" > /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS

        echo "64"     > /usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS
     
    ... to start with
     
    Then increase NUMBER to 128, test again, then try 256.
     
    Remeber to test backup and restore.  Settings go on media server, no restart required.
     
    Martin

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  • mph999's avatar
    mph999
    Level 6
    12 years ago

    Try

        echo "262144" > /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS

        echo "64"     > /usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS
     
    ... to start with
     
    Then increase NUMBER to 128, test again, then try 256.
     
    Remeber to test backup and restore.  Settings go on media server, no restart required.
     
    Martin
  • Marianne's avatar
    Marianne
    Level 6
    12 years ago

    See Symantec NetBackup 52xx Appliance Administrator's Guide: DOC6345

    Setting data buffer parameters on p. 72.

    We see on p. 73 that the default Buffer size is already 262144.

    Default number of data buffers is 30.

    Best to check bptm log for effect of existing buffers before you change anything. 

    Any change should always be documented and effects double-checked in bptm log.

    Look for '... waited for full/empty buffers... ' at the end of each backup and/or duplication.

  • Steve_Lussiaud's avatar
    Steve_Lussiaud
    Level 4
    12 years ago

    Hello,

    just for your information but increase these values consume more shared memory on your server.

    Think to check / tune shared memory availability too.