Page History

...

• 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:
  • Please read https://www.kernel.org/doc/html/latest/vm/zswap.html where it is provided 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.
  • Please read Performance Analysis of Compressed Caching Technique where it is provided that
    • during During the testing procedure LZO (default) algorithm was used for compression and maximum pool percent was set to 20; and
    • see See TABLE I. EFFICIENCY OF ZSWAP MODULE FOR VARIOUS SIZES OF RAM to estimate the extra headroom using zswap with default settings should may provide:
      • From this paper we get that a server with 6GB RAM achieves above 68% efficiency, from which it can be interpreted that the 6GB RAM behaves as if it were 10GB RAM.
        • Be aware though that this is no free lunch: Zswap will use cpu in achieving these gains, so monitoring cpu usage is essential when installing and enabling zswap.
    • Read the conclusion of this paper for insights as to why zswap should not be used on a server with less than 1GB RAM.
  • Don't be tempted to increase maximum pool percent from the default setting of 20: this will affect performance adversely.
    
    

...