$HOME ➟ GNU/Linux ➟ RRDtool: Graphing the DRBD sync rate with RRDtool

This little AWK program converts a series of DRBD's /proc/drbd output into a file that can be loaded into a RRD database. As a result you can see the throughput of all your ressources over time, how they affected each other, and which syncer rate combinations are the most effective.

Color improvements welcome ;-)

Download rrddrbd.awk

Usage

• create a RRD database. It needs three GAUGEs for every ressource in /proc/drbd.
  These will hold (in order)
  • speed
  • average
  • want (drbdsetup /dev/drbdn syncer -r)
  Adapt the --step parameter to the delay in the next command, e.g. 30 seconds.
• while :; do date +%s; date; cat /proc/drbd; sleep 30;done | tee drbd.out
• run the sync or verify
• ./rrddrbd.awk drbd.out > awk2rrd.out
• while read line; do rrdtool update database.rrd "$line"; done < awk2rrd.out
• use the database to create the graphs. Example 1 (ressource comparison), Example 2 (overall throughput)

Pitfalls

You have to "rrdtool create" the database with the --start parameter. Otherwise RRD will refuse to fill the database with entries older than the date of creation!