NetBackup backup of DFSR data is slow

Article:TECH210794  |  Created: 2013-09-23  |  Updated: 2014-05-08  |  Article URL http://www.symantec.com/docs/TECH210794
Article Type
Technical Solution


Issue



Backing up DFSR (Distributed File System Replication) data can take a long time - the larger the dataset, the longer it takes.


Cause



There are several important phases to a NetBackup backup of DFSR data.  

The first phase is the enumeration of the file list.  While in this phase the Activity Monitor will display Begin Writing but no data will be observed as being written.

The bpbkar log for the first phase...

  • begins with:
    INF - in 'pre-backup' mode
  • ends with:
    INF - no more path list entries

The second phase is the taking of the snapshot.

The bpbkar log for the second phase...

  • begins with:
    INF - Entering VssSnapshotVolume
  • ends with:
    INF - VSS Volume Set registered and set in the collection
    INF - ShadowCopy PrePost: End

The third phase is the backing up of the files.  It is during this phase the Activity Monitor will increase the values of KB Written and Files Written.

The bpbkar log for the third phase...

  • begins with:
    INF - in 'backup' mode
  • ends with:
    INF - no more path list entries

For very large DFSR data sets, the first and third phases can take a very long time.


Solution



This resolution for this issue (Etrack 3199748) is included in the following release:

  • NetBackup 7.5 Maintenance Release 7 (7.5.0.7)
  • NetBackup 7.6 Maintenance Release 2 (7.6.0.2)

More information on these releases can be found in the Related Articles linked below.


Supplemental Materials

SourceETrack
Value3199748
Description

When running a backup of a DFSR file tree consisting of 20 million files, bpbkar crashes. Requesting a port of EEB for ET2767908 to be made for 7.5.0.5.




Article URL http://www.symantec.com/docs/TECH210794


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