dumpon and dumpdev

[Barney]

I have dumpdev set to AUTO in rc.conf but after boot “dumpon -l” shows /dev/null. I’ve been doing this for many years and I’ve never seen (or had to worry about) this before. The only difference than usual is the system has a SAS driver (da0 instead of ada0). Can someone explain how the device is chosen and why AUTO would result in no dumpdev found?

 

[SirDice]

Can someone explain how the device is chosen

That answer can be found by reading /etc/rc.d/dumpon:

        [Aa][Uu][Tt][Oo] | '')
                root_hold_wait
                dev=$(/bin/kenv -q dumpdev)
                if [ -n "${dev}" ] ; then
                        dumpon_try "${dev}"
                        return $?
                fi
                if [ -z ${dumpdev} ] ; then
                        return
                fi
                while read dev mp type more ; do
                        [ "${type}" = "swap" ] || continue
                        case ${dev} in
                        *.bde|*.eli)
                                dumpon_warn_unencrypted
                                dev=${dev%.*}
                                ;;
                        esac
                        [ -c "${dev}" ] || continue
                        dumpon_try "${dev}" 2>/dev/null && return 0
                done </etc/fstab
                echo "No suitable dump device was found." 1>&2
                return 1
                ;;

why AUTO would result in no dumpdev found?

There's no suitable device from kenv dumpdev and there's no swap partition in /etc/fstab.

 

[Barney]

Aha! The install script (custom) assumed that da0 was a USB so it didn’t include the swap device when it created the fstab. It would be so cool if SAS drives came up as ada but we’ve had that discussion many times over the past 20 years.

 

[SirDice]

I usually remove it from /etc/rc.conf, it's really only useful to capture crash information, and my systems rarely, if ever, do

 

[Barney]

Well we live in different worlds....