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rajeshthink's avatar
12 years ago

Linux SAN media server performances issue --- Low speed

Greeting to all ...

I have two SAN media server which we recently build , We did certain test and from SAN media server A we are getting speed of 70 -100 MB/s , where as from SAN media server B we get max thoughput of 20 -30 MB/s .

-----Zoning are perfect

 

 

Cheer,

Rajesh Kumar

  • Start with troubleshooting outside of NBU. 

    1. Test read speed from disk using bpbkar test:
    Increase logging level to 1
    Create /usr/openv/netbackup/logs/bpbkar folder
    Run: /usr/openv/netbackup/bin/bpbkar -nocont -dt 0 -nofileinfo -nokeepalives <filesystem> > /dev/null  
    Check results in bpbkar log

    If read performannce is good, test write speed to tape:

    2. Load a scratch/blank tape in a drive.
    Use tar or cpio to write backup to drive.
    Note time taken to write backup.

    If both methods above shows good performance, then tune NBU buffers.
    Create these 2 files: 

    /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS 
    add a value of 
    262144

    /usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS 
    add a value of 32 (can be more if server resources are sufficient)

    Ensure bptm log folder exists to verify effect of buffer settings.
     

4 Replies

  • Start with troubleshooting outside of NBU. 

    1. Test read speed from disk using bpbkar test:
    Increase logging level to 1
    Create /usr/openv/netbackup/logs/bpbkar folder
    Run: /usr/openv/netbackup/bin/bpbkar -nocont -dt 0 -nofileinfo -nokeepalives <filesystem> > /dev/null  
    Check results in bpbkar log

    If read performannce is good, test write speed to tape:

    2. Load a scratch/blank tape in a drive.
    Use tar or cpio to write backup to drive.
    Note time taken to write backup.

    If both methods above shows good performance, then tune NBU buffers.
    Create these 2 files: 

    /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS 
    add a value of 
    262144

    /usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS 
    add a value of 32 (can be more if server resources are sufficient)

    Ensure bptm log folder exists to verify effect of buffer settings.
     

  • GEN_DATA directive is pretty nice to isolate performance issue. You can measure performance between media server and storage unit in NetBackup. No need to mount tape manually.

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

  • I Just change the Data_buffer_size from 128 to 256 and Now i see a fair speed its writing the data.

    Hope this resolve the issue , Also the backup use to take 4 days to complete Now its taking just 2 days..

    so think the next step would be changing it o 512.

     

    any suggestion are Appriciated .

     

    cheer,

    Rajesh Kumar