Re: dumpdev in loader.conf vs rc.d/dumpon

On 23/09/2015 19:44, Conrad Meyer wrote:
> On Wed, Sep 23, 2015 at 9:05 AM, Andriy Gapon <avg_at_freebsd.org> wrote:
>> On 23/09/2015 18:59, Conrad Meyer wrote:
>>> On Wed, Sep 23, 2015 at 7:37 AM, Andriy Gapon <avg_at_freebsd.org> wrote:
>> Because that's how I read the code in sys/geom/geom_dev.c.  Especially
>> init_dumpdev() - I believe that devtoname() returns a device name without '/dev/'.
> 
> I don't think that's the primary use of the variable.

See below.

>>> I don't see etc/rc.d/dumpon prepending /dev to anything.
>>
>> Right, that's why I posted my message (bug report).
> 
> I think the use of the variable "dumpdev" in GEOM probably
> could/should be dropped.

The way I found this variable was that I needed to set up a dump device before
init.  GEOM can do that, if dumpdev is set in kenv, as soon as a configured
device is available.
If a system survives until rc.d/dumpon can run, then why bother with setting
dumpdev in kenv - dumpdev in rc.conf would work.

> Alternatively (perhaps it is a mechanism for collecting crash dumps
> before init / /etc/rc start?)

Exactly.

> the GEOM dumpdev code could skip over a
> "/dev/" prefix when comparing against devname(), so that the GEOM use
> of the variable matches the etc/rc.d/dumpon use of the variable.

Yes, that's another option.  But, IMO, dumpdev in kenv is only really useful if
rc.d/dumpon doesn't have a chance to run.  So, when rc.d/dumpon is able to run
it can make a tiny concession to the way GEOM works.

I do not have a strong opinion.  Either option, rc.d/dumpon change or geom_dev
change, is fine with me.

-- 
Andriy Gapon