http://www.squid-cache.org/mail-archive/squid-users/199909/0374.html (admittedly from 1999, predating squid3) suggests this isn't actually a ulimit problem, but a reserved FD crisis.
2016/03/08 06:54:04| Reserved FD adjusted from 100 to 64538 due to failures
This hints that it basically reserved nearly all of them. This can't be right.
http:// www.squid- cache.org/ mail-archive/ squid-users/ 199909/ 0374.html (admittedly from 1999, predating squid3) suggests this isn't actually a ulimit problem, but a reserved FD crisis.
2016/03/08 06:54:04| Reserved FD adjusted from 100 to 64538 due to failures
This hints that it basically reserved nearly all of them. This can't be right.