IO Rules of Thumb

• %b
  • < 5% => no worries
  • > 30% => problem
• svc_t
  • if %b < 5%, ignore
  • 10-50 ms okay
  • 50-1500 ms is a problem (longer latency)
    direct effect on user response time
• %w
  • 0% - SCSI bus probably clear
  • 0-5% - bus busy
  • > 5% - SCSI bus very busy