Forum Discussion

LubosDvorak's avatar
LubosDvorak
Level 4
17 days ago

Duplication of small images into MSDP-C takes longer time as usual

Hello,
I have a serious performace issue with duplication of many images to an MSDP-C pool.

NetBackup 10.5.0.1 is duplicating images to the MSDP-C pool at an on-premise S3. There are about 600 backup images created per hour. The duplication jobs cannot process this number at the same rate, although several dozen of them are running simultaneously.

The problem is not in the volume of data - the vast majority of images are database log backups of tens of kB to several MB in size. The problem is that the duplication of even the smallest image takes several minutes.

An example: duplicating one image of 670 kB took an incredible 14 minutes. I see large delays between individual actions in the job details. Please see details of the duplication of this image below.

The media server's HW resources are under-loaded.

As long as a small number of images were duplicated per hour, duplicating individual images took an average of 2 minutes - that was fine.

What is the cause of the slowdown and how can I eliminate the cause?

Thank you,
Lubos

Example of a duplication job details with long delays:

26. 6. 2025 10:02:53 - Info bpduplicate (pid=125788) The data-in-transit encryption (DTE) is disabled, as the global DTE mode is set to 'Preferred Off'
26. 6. 2025 10:02:53 - Info bpdm (pid=3633773) started
26. 6. 2025 10:02:53 - started process bpdm (pid=3633773)
26. 6. 2025 10:02:53 - requesting resource  @aaaaw
26. 6. 2025 10:02:53 - granted resource  MediaID=@aaaaw;DiskVolume=PureDiskVolume;DiskPool=Pool4;Path=PureDiskVolume;StorageServer=MediaServer1.x.y;MediaServer=MediaServer1.x.y
26. 6. 2025 10:02:54 - Info bpdm (pid=3633773) requesting nbjm for media
26. 6. 2025 10:03:37 - begin writing
26. 6. 2025 10:03:37- end writing; write time: 0:00:00
26. 6. 2025 10:06:08- begin writing
26. 6. 2025 10:06:08 - Info bpdm (pid=3633773) Waiting for storage server MediaServer1.x.y, disk volume PureDiskVolume
26. 6. 2025 10:07:08 - Info bpdm (pid=3633773) Transferred 688937 bytes, to storage server MediaServer1.x.y, disk volume PureDiskVolume 
26. 6. 2025 10:08:08 - end writing; write time: 0:02:00
26. 6. 2025 10:08:44- Info MediaServer1.x.y (pid=3633773) StorageServer=PureDisk:MediaServer1.x.y; Report=PDDO Stats for (MediaServer1.x.y:PureDiskVolume): scanned: 672 KB, CR sent: 25 KB, CR sent over FC: 0 KB, dedup: 96.3%, cache disabled, where dedup space saving:0.0%, compression space saving:96.3%, new transferred data unencrypted
26. 6. 2025 10:17:08- Info bpdm (pid=3633773) EXITING with status 0

3 Replies

  • LubosDvorak's avatar
    LubosDvorak
    Level 4
    17 days ago

    Please note these delays:

    26. 6. 2025 10:03:37- end writing; write time: 0:00:00
    26. 6. 2025 10:06:08- begin writing
    ....
    26. 6. 2025 10:08:44- Info MediaServer1.x.y (pid=3633773) StorageServer=PureDisk:MediaServer1.x.y; Report=PDDO Stats for (MediaServer1.x.y:PureDiskVolume): scanned: 672 KB, CR sent: 25 KB, CR sent over FC: 0 KB, dedup: 96.3%, cache disabled, where dedup space saving:0.0%, compression space saving:96.3%, new transferred data unencrypted
    26. 6. 2025 10:17:08- Info bpdm (pid=3633773) EXITING with status 0

    • quebek's avatar
      quebek
      Moderator
      14 days ago

      Hello

      Well such issues are hard to nail down. I would have started with the bpdm logs on media server. So add to media server's bp.conf file VERBOSE = 5 and after a duplication grep the log for given bpdm pid. of course the bpdm directory has to be created ;) also try to leverage command duplicatetrace ....

      If these outcomes will not point to any direction - open a case with Cohesity ;)

      • LubosDvorak's avatar
        LubosDvorak
        Level 4
        2 days ago

        Hello quebek​ ,

        Thank you for your reply.
        I checked the bpdm logs and ran the duplicatetrace command but I haven't come to any conclusion.

        I opened a case with Cohesity.
        Support advised me to verify the configuration using the Deduplication Guide and the Performance and Tuning Guide. In addition to the above, I was advised to contact Cohesity professional services if more information was needed.

        Meanwhile I have observed that duplication jobs have performance problems for such a client and policy when the /msdp/databases/catalog/dsid/CLIENT/POLICY directory is larger then approx. 100 MB.