Re: Looks like the arm 20220805 snapshots are still odd, so probably kern.geom.part.mbr.enforce_chs=0 was still in use

On 2022-Aug-9, at 11:15, Glen Barber <gjb@FreeBSD.org> wrote:

> On Tue, Aug 09, 2022 at 02:06:14PM -0400, Ed Maste wrote:
>> On Sun, 7 Aug 2022 at 18:43, Glen Barber <gjb@freebsd.org> wrote:
>>> 
>>> Will do.  I’ll commit the suggested change to main tomorrow.
>>> 
>>> Thank you for your vigilant investigation.
>> 
>> Shall I commit the enforce_chs check now?
>> ---
>> commit 6ee7d69e6b526f35789b23ba570025f1c3b39c1a
>> Author: Ed Maste <emaste@FreeBSD.org>
>> Date:   Tue Jul 19 16:47:49 2022 -0400
>> 
>>    release: ensure enforce_chs sysctl is 0
>> 
>>    We do not want CHS-based alignment for VM or SD card release images.
>> 
>>    Sponsored by:   The FreeBSD Foundation
>> 
>> diff --git a/release/tools/arm.subr b/release/tools/arm.subr
>> index 6e4ae731a0b9..01c5303cd4e1 100644
>> --- a/release/tools/arm.subr
>> +++ b/release/tools/arm.subr
>> @@ -62,6 +62,10 @@ umount_loop() {
>> }
>> 
>> arm_create_disk() {
>> +       if [ $(sysctl -n kern.geom.part.mbr.enforce_chs) != 0 ]; then
>> +               return 1
>> +       fi
>> +
>>        # Create the target raw file and temporary work directory.
>>        chroot ${CHROOTDIR} gpart create -s ${PART_SCHEME} ${mddev}
>>        if [ "${PART_SCHEME}" = "GPT" ]; then
>> 
> 
> Good question.  Do we still want to ensure it is set to '0'?  I'm a bit
> confused from the back-and-forth on the original thread.
> 
> If we do want to ensure it is set to '0', yes, please go ahead.
> 

Hopefully this week's experiment with explicitly avoiding BSD
and freebsd-ufs having the same offset inside BSD (avoiding
both offsets being zero) will allow the UFS labeling to work
right: freebsd-ufs being tied to a unique offset inside BSD.

I really doubt that using kern.geom.part.mbr.enforce_chs=1 to
cause the offsets to be different is reasonable, despite that
it happens to make them distinct: the freebsd-ufs offset is
better controlled explicitly elsewhere.

===
Mark Millard
marklmi at yahoo.com