Unresponsive system

[Janos Dohanics]

Hello List,

Earlier today, one of my servers became unresponsive:

# less /var/log/messages
[...]
Mar 28 11:43:33 cortina pop3[4090]: Expunged 1 messages from user.[...]
Mar 28 11:43:33 cortina pop3[4090]: USAGE [...] user: 0.000000 sys: 0.003032
Mar 28 11:43:33 cortina pop3[4090]: counts: retr=<1> top=<0> dele=<1>
Mar 28 11:43:34 cortina pop3[3877]: login: [...].fios.verizon.net [a.b.c.d] [...] plaintext User logged in SESSIONID=<cortina[...]>
Mar 28 11:43:34 cortina pop3[3877]: USAGE [...] user: 0.000000 sys: 0.002152
--> Mar 28 11:43:34 cortina pop3[3877]: counts: retr=<0> top=<0> dele=<0>
--> Mar 28 11:45:30 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:45:30 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:45:39 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:39 cortina kernel: sonewconn: pcb 0xfffff80003e82740: pru_attach() failed
Mar 28 11:45:41 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:45:41 cortina last message repeated 3 times
Mar 28 11:45:42 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:42 cortina kernel: sonewconn: pcb 0xfffff80003e82740: pru_attach() failed
Mar 28 11:45:44 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:45 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:45 cortina kernel: sonewconn: pcb 0xfffff80003e82740: pru_attach() failed
Mar 28 11:45:51 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:54 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:45:59 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:46:02 cortina last message repeated 3 times
Mar 28 11:46:03 cortina kernel: sonewconn: pcb 0xfffff80003e831d0: pru_attach() failed
Mar 28 11:46:18 cortina last message repeated 3 times
Mar 28 11:46:19 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:46:19 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:46:21 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:46:23 cortina kernel: sonewconn: pcb 0xfffff80003e831d0: pru_attach() failed
Mar 28 11:46:24 cortina kernel: sonewconn: pcb 0xfffff80003e82740: pru_attach() failed
Mar 28 11:46:24 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:46:28 cortina kernel: sonewconn: pcb 0xfffff80003e831d0: pru_attach() failed
Mar 28 11:46:30 cortina kernel: sonewconn: pcb 0xfffff80003e82cb0: pru_attach() failed
Mar 28 11:46:33 cortina kernel: sonewconn: pcb 0xfffff80003e831d0: pru_attach() failed
Mar 28 11:46:38 cortina kernel: sonewconn: pcb 0xfffff80003e82570: pru_attach() failed
Mar 28 11:46:38 cortina kernel: sonewconn: pcb 0xfffff80003e831d0: pru_attach() failed
Mar 28 11:49:19 cortina syslogd: kernel boot file is /boot/kernel/kernel

--> It's notable that there were no entries in /var/log/messages for
almost 2 minutes before the sonewconn error happened.

The system is FreeBSD 11.0-STABLE #0 r314885 amd64. It is mostly used
to run Cyrus, Postfix, Amavisd, Clamd. Kernel is not customized, except
for "ident".

Could this problem be related to the additional swap space provided by a swapfile?

# cat /etc/fstab
# Device	Mountpoint	FStype	Options	Dump	Pass#
/dev/ada0p2	none		swap	sw	0	0
/dev/ada0p3	/		ufs	rw	1	1
/dev/ada0p4	none		swap	sw	0	0
md0		none		swap	sw,file=/swapfile,late	0	0

# swapinfo -hm
Device          1M-blocks     Used    Avail Capacity
/dev/ada0p2           256     241M      15M    94%
/dev/ada0p4           750     290M     460M    39%
/dev/md0             4096     289M     3.7G     7%
Total                5102     820M     4.2G    16%

I'd appreciate your advice.

-- 
Janos Dohanics