This affected me on a laptop using atop:i386 1.26-2 on Ubuntu 14.04.5 (upgraded from 12.04 I think(. I'd woken the laptop shortly before midnight, and at about 3am, the wireless connection was up but with no DNS.
$ sudo dnsmasq
dnsmasq: failed to open pidfile /var/run/dnsmasq.pid: No space left on device
This affected me on a laptop using atop:i386 1.26-2 on Ubuntu 14.04.5 (upgraded from 12.04 I think(. I'd woken the laptop shortly before midnight, and at about 3am, the wireless connection was up but with no DNS.
$ sudo dnsmasq
dnsmasq: failed to open pidfile /var/run/ dnsmasq. pid: No space left on device
There was 300M in /run/atop/atop.acct
root 4999 1 0 981 1948 0 00:00 ? 00:01:35 /usr/bin/atop -a -w /var/log/ atop/atop_ 20171029 600
This was in /etc/cron.d/atop
# start atop daily at midnight
0 0 * * * root invoke-rc.d atop _cron
So is this a packaging problem? I'd agree with urraca that /var/run (symlink to tmpfs /run) is the wrong place. How about /tmp?