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kakaluru's avatar
Level 4
10 years ago

My weekend back up is running very very slow

Hello Marianne

After resolving catalog issues etc.I don't know the reasons my weekend back up is running very very slow.

Let  me know which log files you need to check this.


**** Moved to new discussion from Catlogback up Delay ****

  • I understood but we never faced this issue earlier.

    Well, there is no way that NetBackup can be at fault since the SAME binaries have been in place for way too many years!

    This is Windows... when last did you reboot it?

    What is the Windows version and patch level?
    Any chance that Windows updates were installed recently? 

    On  which date did the slow backups start?
    I do not have the time to go through all the logs...

    The files are quite small. In future, PLEASE copy files to .txt (e.g. bptm042415.txt) and upload as File attachments.
    .txt files can be viewed online. zipfiles need to be downloaded and extracted. .log files cannot be viewed on a mobile device.

  • What are the patches you want me to tell. 



    I was asking you to look for any changes outside of NBU. We know that the ONE THING that has NOT changed is NBU. 

    Looking at the log file, we see the following:

    04:19:55.586 [2796.884] <2> write_data: waited for full buffer 36317 times, delayed 619034 times

    This means that NBU (bptm buffer) was waiting for data. 
    The problem is therefore outside of NBU. 
    You need to look at the other components in the data path:
    Client disk -> Client NIC -> network -> Media server NIC -> bptm buffer -> tape drive

    We have in the past seen that Windows updates has enabled TCP Chimney, which resulted in socket errors or just very slow throughput.

    Check TCP Chimney settings on master/media server and client(s): 

  • Speak to your OS and network administrators - they should be able to explain to you the data flow that is involved in a backup.

    As far as TCP Chimney is concerned - please read the TN. 
    Or ask the OS Admin to help.

    More info about general troubleshooting for slow backups:

    Overview of NetBackup performance testing. 
    (This TN contains a diagram that explains the data path)

    This doc is for newer NBU versions, but the principals remain the same: 

    Symantec NetBackup™ 7.0 - 7.1 Backup Planning and Performance Tuning Guide 
    (Click on the 'Attachments' link.)

  • Seeing that the problem is fixed by restarting the client, you need to have a look at Windows logs on the client.

    Start with Windows Event Viewer System and Application logs.

    Since nothing at NBU level has changed, the components that are refreshed by a reboot can be confirmed with Windows sysadmin.

    Just some of the components that comes to mind:

    Memory & cpu
    Path from OS to disk
    Disk drivers
    Network card

    There is nothing at NBU level to troubleshoot.
    bpbkar logs on the client before and after reboot will simply confirm that read speed was slow before the reboot and faster after the reboot.
    NBU can only report the transfer rate, not what is causing slow or fast transfer.

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