Question

What values are used in OACI VE peformance graphs? How OACI gets CPU, RAM, traffic resources usage statistics of virtual machines and containers?

Answer

OACI uses Virtuozzo dispatcher service data obtained via Virtualization SDK to get the "real" usage statistics of virtual machines and containers. The same details can be fetched by prlctl statistics command directly on the hardware node. These values are closer to the top command inside the virtual machines and containers.

RAM usage calculation changed during the lifetime of Virtuozzo:

  • since VZ 6.0 Update 8: guest.ram.usage - guest.ram.cached
  • before VZ 6.0 Update 8: guest.ram.usage

paciagent.log logs the results of the statistic calculations. Search for entries containing hostname of the VE to see the usage for CPU, RAM, Incoming and outgoing public and private traffic. Here is the example from logs:

2016-05-30 10:10:37,866 DBG perfstats: [1234567.TESTVM001] count 198 private in/out [0 1095163] public in/out [3356849957 13839377] cpu 4% (4%) ram 689mb state 0 @[agent.c][200][dump_statistics][450472])
2016-05-30 10:10:37,866 DBG perfstats: [1234567.TESTVM001] count 198 private in/out [0 1185552] public in/out [3901628919 251487248] cpu 1% (1%) ram 364mb state 0 @[agent.c][200][dump_statistics][450472])
2016-06-06 13:12:31,719 DBG perfstats: [1234567.TESTVM001] count 201 private in/out [0 1405852] public in/out [4307611143 17351458] cpu 4% (4%) ram 691mb state 0 @[agent.c][200][dump_statistics][948000])
2016-06-06 13:12:31,719 DBG perfstats: [1234567.TESTVM001] count 201 private in/out [0 1499044] public in/out [5121129762 637465879] cpu 2% (2%) ram 606mb state 0 @[agent.c][200][dump_statistics][948000])

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