RRDTool

http://oss.oetiker.ch/rrdtool/index.en.html - RRDTool homepage

Create a Database

The following example creates a RRD database to hold an ESX's aggregated (average of all cores) CPU data with;

• Raw data held for 12 hrs (realtime)
• 5 min average (with max and min values) for 24 hrs (daily)
• 20 min average (with max and min values) for 7 days (weekly)
• 60 min average (with max and min values) for 31 days (monthly)
• 1 day average (with max and min values) for 365 days (yearly)

In order to achieve the rolled-up averages, its necessary to calculate;

• The number of raw data points required for that average (eg to be able to calculate a 5 min average)
• The number of those averages to store (eg to be able to have a day's worth of 5 min average data)

Its also necessary to calculate how much raw data you want to store (if any)

• Raw
  • Data is available every 20 secs
  • Therefore 3 intervals per min
  • Therefore 3 x 60 = 180 raw data points per hour
  • Therefore 12 x 180 = 2160 raw data points (to provide 12 hrs of data)
• Daily

15 intervals = 5min (period to average over) 1440 av points = 24 hr coverage

60 intervals = 20 mins 504 av points = 7 days coverage

180 intervals = 1 hr 744 av points = 31 days coverage

4320 intervals = 1 day 366 av point = 1 yr coverage

rrdtool create esx1-cpu.rrd --step 20 \ DS:CPU-Aggregate:GAUGE:40:0:100 \ RRA:AVERAGE:0.5:1:2160 \ RRA:AVERAGE:0.25:15:1440 \ RRA:MIN:0.25:15:1440 \ RRA:MAX:0.25:15:1440 \ RRA:AVERAGE:0.25:60:504 \ RRA:MIN:0.25:60:504 \ RRA:MAX:0.25:60:504 \ RRA:AVERAGE:0.25:180:744 \ RRA:MIN:0.25:180:744 \ RRA:MAX:0.25:180:744 \ RRA:AVERAGE:0.25:4320:366 \ RRA:MIN:0.25:4320:366 \ RRA:MAX:0.25:4320:366