swapctl out of memory

[Thomas Klausner <tk%giga.or.at@localhost>]

Hi!

My always-on-about-24-days-up NAS running 6.0.1/amd64 didn't let me
login remotely any longer, so I went to the console. There everything
worked fine including mtr traces to some hosts, but I couldn't ssh out
of the machine either.

Out of ideas, I rebooted. During shutdown, it took quite some time and
then wrote (from memory):
swapctl /dev/something: out of memory

After the reboot, everything worked fine again.

I haven't seen behaviour like that before (ssh doesn't work,
traceroute/mtr do) and the swapctl message looks very weird as well.
Any ideas what kind of problem could be behind this behaviour?
 Thomas