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Yogesh_Patil's avatar
Yogesh_Patil
Level 4
3 years ago

Netbackup Appliance to Tape drive performance

Dear All,

I have small environment Master 9.1 + Appliance 4.1 (With connected Tape library having 4 FC LTO7 Tapes drives)
Appliance having FC connectivity but may be its not activated.
Tape Library 4 drive connected on Fiber. 
Currently Tape backup writing data over the LAN

Storage Unit details:
Storage Device = HCART
DENSITY : HCART = 1/2 Inch Cartridge
Maximum concurrent Writen Drives: 4
Enabled Multiplexing Maximum Streams per drive: 2
Reduce fragment Size to : 1048575 Megabytes

I have attached appliance Fiber setting details.

Can you please suggest How I will improve my tape backup performance? 

What is best value on Media Multiplexing and Is will complete my pending SLP tape backup job in case I will increase value from 2 to 20?

  • Nicolai's avatar
    Nicolai
    Moderator
    3 years ago

    Hi Yogesh_Patil 

    Not a appliance expert but I would ensure Netbackup has the following setting set:

    NUMBER_DATA_BUFFERS = 256 or 512 (not default value)
    SIZE_DATA_BUFFERS = 262144 (default value)

    You can afterwards check the performance using the GEN_DATA_DIRECTIVE. You should get native LTO7 writing/reading speed.

    See these tech note for reference:

    NET_BUFFER_SZ, SIZE_DATA_BUFFERS and NUMBER_DATA_BUFFERS on UNIX - how they work and how to configure them. (Please disregard NET_BUFFER_SZ - setting is deprecated).

    https://www.veritas.com/support/en_US/article.100000498

    How to use the GEN_DATA file list directives with NetBackup for UNIX/Linux Clients for Performance Tuning

    https://www.veritas.com/support/en_US/article.100030600

    MPX = 4 seems to fair value, but increasing MPX count will not help on SLP backlog.

    Best Regrads
    Nicolai

     

    • davidmoline's avatar
      davidmoline
      Level 6
      3 years ago

      Hi Yogesh_Patil 

      To expand on what Nicolai said, media multiplexing can only help with direct backup to tape. Any type of duplication operation (SLP or manual) is only single streamed. 

      One thing that may help if this is not done already is to give each tape drive it's own FC port to operate from (and looking at the fibre settings this does look ot be the case). 

      David

    • Nicolai's avatar
      Nicolai
      Moderator
      3 years ago

      Also - it may be wort while mentioning. If reading/writing speed cannot be achieved, try using a cleaning tape. The health of tape drives does matter.

      • Yogesh_Patil's avatar
        Yogesh_Patil
        Level 4
        3 years ago

        Thanks Nicolai & David for reply.

        Current Backup configuration:
        Configured SLP duplication
        1st Backup (Primary) goes to Appliance1
        2nd backup goes form Appliance1 to Appliance2 (Over WAN)
        3rd backup goes from Appliance2 to Tape Library (Over loacl LAN/FC)

        I am still not cleared the "How to use the GEN_DATA file list directives with NetBackup" I will check again.

        Below are the Appliance2 details:
        NET_BUFFER_SZ, SIZE_DATA_BUFFERS and NUMBER_DATA_BUFFERS current configuration details as below : 
        # cat /usr/openv/netbackup/db/config/SIZE_DATA_BUFFERS = 262144
        # cat /usr/openv/netbackup/db/config/NUMBER_DATA_BUFFERS = 30
        # cat /usr/openv/netbackup/NET_BUFFER_SZ = 0

        CLISH>Setting>FibreTransport Initiator Show
        fc transport disabled
        CLISH>Setting>FibreTransport Target Show
        - [Info] Fibre Transport Deduplication is disabled.
        - [Info] The Fibre Transport server is disabled.

        Appliance2 Web: Setting-->Network-->Fibre Transport : find the attached snapshot for more information.
        As per Web portal FC connectivity showing disabled.
        But When I click it showing connected (Right now I am not save this setting)
        Do have idea If I enable Fiber Transport target mode, What will happened?

        Current success Tape backup job details (Appliance2 to Tape) : Showing CR received over FC, so confused that if attached file showing FC disabled, than how job details showing backup success over the FC?
        Oct 20, 2021 12:38:26 PM - Info bptm (pid=27519) waited for full buffer 22241 times, delayed 58158 times
        Oct 20, 2021 12:38:26 PM - end reading; read time: 0:03:45
        Oct 20, 2021 12:38:31 PM - Info bpdm (pid=27605) completed reading backup image
        Oct 20, 2021 12:38:31 PM - Info bpdm (pid=27605) EXITING with status 0
        Oct 20, 2021 12:38:32 PM - Info appliance2 (pid=27605) StorageServer=PureDisk:appliance2; Report=PDDO Stats for (appliance2): read: 81936213 KB, CR received: 49485386 KB, CR received over FC: 0 KB, dedup: 0.0%
        Oct 20, 2021 12:38:36 PM - Info bptm (pid=27519) EXITING with status 0 <----------
        Oct 20, 2021 12:38:36 PM - end Duplicate; elapsed time 0:18:15
        The requested operation was successfully completed.  (0)

        Tape drive leaning : No issue, I am doing regulars.

        I assume that once I will enable Fiber Transport target mode tape backup will faster...