Page History

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• ABI 1 (NMIS 8)
  • In omk/conf/opCommon.nmis:
    • omkd_workers is set at 10 by default. Try reducing this number to 2 and then restart the omkd service.
      If you THEN find YOU need more omkd_workers, increment this value by one and test again until you get to a suitable value for omkd_workers
    • /omkd/omkd_max_requests: 100 to 500 (start at 100 and increase from this value if needed)
      
      
• ABI 2 (NMIS 9)
  • In omk/conf/opCommon.json:
    • omkd_workers is set at 10 by default. Try reducing this number to 2 and then restart the omkd service.
      If you THEN find YOU need more omkd_workers, increment this value by one and test again until you get to a suitable value for omkd_workers
    • /omkd/omkd_max_requests: 100 to 500 (start at 100 and increase from this value if needed)
  • in nmis9/conf/Config.nmis:
    • /system/nmisd_worker_max_cycles: 100
      
      
• Consider installing and using zswap, with its default settings, provided the server has more than 1GB RAM:
  • https://www.kernel.org/doc/html/latest/vm/zswap.html provides that:
    • Overcommitted guests that share a common I/O resource can dramatically reduce their swap I/O pressure, avoiding heavy handed I/O throttling by the hypervisor.
      This allows more work to get done with less impact to the guest workload and guests sharing the I/O subsystem.
    • Users with SSDs as swap devices can extend the life of the device by drastically reducing life-shortening writes.
  • Performance Analysis of Compressed Caching Technique
    
    • See the CONCLUSION of this paper for insights as to why zswap should not be used on a server with less than 1GB RAM.
  • https://www.ibm.com/support/pages/new-linux-zswap-compression-functionality provides thatthat for a server with 10GB RAM and 20% zswap pool size: 
    • On x86, the average zswap compression ratio was 3.6
    • For the x86 runs, the pool limit was hit earlier - starting at the 15.5 GB data point (for a server with 10GB RAM and 20% zswap pool size)
  • Don't be tempted to increase maximum pool percent from the default setting of 20: this will most likely affect performance adversely.
  • Command to view zswap info during operation:
    • sudo grep -rRn . /sys/kernel/debug/zswap/
      
      

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