Obtaining kernel core dumps


#1

I experience random crashes on unstable, so I wanted to get some useful info and try to learn something from it or at least send it to devs

after reading this thread I tried to get kernel dumps - without success so far.

some diagnostic info

boot environment now (N) … 12.0-CURRENT-up-20180105_040512 NR 2018-01-05

$ cat /etc/sysctl.conf | grep coredump

kern.coredump=1

$ cat /etc/rc.conf

...
dumpdev=label/swap0.eli
# tried /dev/label/swap0.eli

$ dumpon -l

/dev/null

$ geli list

Geom name: label/swap0.eli
State: ACTIVE
EncryptionAlgorithm: AES-XTS
KeyLength: 128
Crypto: hardware
Version: 7
Flags: ONETIME, W-DETACH, W-OPEN
KeysAllocated: 1
KeysTotal: 1
Providers:
1. Name: label/swap0.eli
   Mediasize: 4294963200 (4.0G)
   Sectorsize: 4096
   Mode: r1w1e0
Consumers:
1. Name: label/swap0
   Mediasize: 4294966784 (4.0G)
   Sectorsize: 512
   Stripesize: 0
   Stripeoffset: 3465564160
   Mode: r1w1e1

$ sudo ls -all /var/crash

total 7
drwx------ 2 root wheel 3 Dec 20 18:49 .
drwxr-xr-x 25 root wheel 40 Jan 5 04:05 ..
-rw-r--r-- 1 root wheel 5 Dec 20 18:49 minfree