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Vickie's avatar
Vickie
Level 6
10 years ago

Backup running very slow

Hi Experts,

I need your urgent assistance on a long running backup, below given are the details.

Master OS : Linux Master NBU Version : 7.0.1

Client OS : Windows Client NBU Version : 7.0.1

Issue : Backup of few drives taking more than 70 hours to complete. 

Data size is around 2 Tb.

12172 Kb/sec is throughput getting for backup.

How can I make the backup run fast, and what could the reason for slow backup. What are the steps to troubleshoot.

Would really appreciate your reverts and assistance

7.1.x and Earlier
Backup and Recovery
Linux
NetBackup
Troubleshooting
  • Nicolai's avatar
    Nicolai
    10 years ago

    The Symantec NetBackup Backup Planning and Performance Tuning Guide  has som very good hints for resolving performance issues

    http://www.symantec.com/docs/DOC7449

    Chapter 7 (page 106)

    You can also verify that the master server is fit for use by using the GEN_DATA file directive. If backup/restore speed is good with in memory generated data you can quickly move toward the network and client.

    http://www.symantec.com/docs/TECH75213

    PS: I don't think disabling WFOB will help at all.

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  • Vickie's avatar
    Vickie
    Level 6
    10 years ago

    Will it be fine, If I will disable WOFB for this windows client. Can this be help in increasing the backup speed.

    If I'll disable WOFB, Would that cause any backup failure or harm to backup the data.

     

     

  • Nicolai's avatar
    Nicolai
    Moderator
    10 years ago

    The Symantec NetBackup Backup Planning and Performance Tuning Guide  has som very good hints for resolving performance issues

    http://www.symantec.com/docs/DOC7449

    Chapter 7 (page 106)

    You can also verify that the master server is fit for use by using the GEN_DATA file directive. If backup/restore speed is good with in memory generated data you can quickly move toward the network and client.

    http://www.symantec.com/docs/TECH75213

    PS: I don't think disabling WFOB will help at all.

  • watsons's avatar
    watsons
    Level 6
    10 years ago

    How many files are you backing up?

    Also if there was a previous successful backup that took a long time, please show it so we can find out if there is any "waited for [full|empty] buffer" message in bptm.

  • Marianne's avatar
    Marianne
    Level 6
    10 years ago

    12172 Kb/sec is throughput getting for backup.

    Looks like max speed seen for 100BaseT connection!

    If  client and media server are on 1Gb network, first step in troubleshooting slow transfer rate is to verify client's ability to read from disk.

    Use bpbkar32 to test client read speed. Choose a folder on Client's problematic drive with at least 2 GB in size and bpbkar in cmd window to read data and backup to 'null' device.
    When you issue the command, you will be returned to the prompt. Use Windows task manager to see when bpbkar process stops and then check bpbkar log.
    Instructions in this TN: http://www.symantec.com/docs/TECH1754 

    If this read speed is slow, you need to speak to server ownwer and/or storage team.
    Server owner needs to check fragmentation on the drive and storage team must check lun/volume layout.

    Next step is to confirm that TCP Chimney is disabled on Windows client:
    http://www.symantec.com/docs/TECH60844 

    If the client volume is on a SAN attached raid lun, you can read multiple streams from the same volume.
    Select 'Allow multiple data streams' in policy attributes, ensure 'Max Jobs Per Client' on master server Host Properties is set to 2 or more (4 is a good average), then divide Backup Selection in 2-4 streams. e.g:

    NEW_STREAM
    Z:\folder\a*
    Z:\folder\b*
    Z:\folder\....
    Z:\folder\....
    NEW_STREAM
    Z:\folder\....
    Z:\folder\....
    ....
     

    PS: 
    Disabling WOFB will probably not make a difference...

    Obviously some sort of consistent folder structure is assumed for my example.
    Speak to server owner to see what top level folder structure looks like.

  • Vickie's avatar
    Vickie
    Level 6
    10 years ago

    Thanks all for your suggestion, will get back to you once will done with the above