[rrd-users] Can small writes generate a lot of faults?

[Daniel Hilst Selli]

My case is this, I'm using collectd [1] with rrdtool [2] to monitor some 
server.
a) When I enable rrdtool plugin I can grab collectd process as top page 
fault process on top command.
PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  nFLT COMMAND
20128 root      18   0 4105m  35m  17m S  7.9  0.3 0:09.62  22k 
/opt/collectd/sbin/collectd
b) Disabling rrdtool plugin dramastically decrease the number of page 
faults of collectd.
c) I know that rrdtool plugin is known to generate a lot of small 
writes, as stated in [3]. Also I know the parameters to improving 
collectd's cache usage to save I/O, but this is not the question here..

AFAIK, major page faults are generated when data that is not yet present 
on RAM is loaded from disk, but in this case data is being write do 
disk, I can't
see how writes can generate faults, but still, it seems that is 
happening, ... !?

Is that possible?

Cheers,

[1] http://www.collectd.org
[2] http://oss.oetiker.ch/rrdtool/
[3] https://collectd.org/wiki/index.php/Inside_the_RRDtool_plugin