So I’m using collectd to monitor my systems. For a couple of machines it was fine, but as soon as it got more collectd caused a constant load on my disks due to all the RRD files that need to be written.
<Plugin rrdcached> DaemonAddress "unix:/var/run/rrdcached.sock" DataDir "/var/db/collectd/" CreateFiles true CreateFilesAsync false CollectStatistics true </Plugin>
Restarting collectd the results became immediately noticeable:
The blue read spike is from a backup job that runs at midnight
In conclusion: The server has now less free memory but more free IO time.