Re: upgrade stable/12 -> stable/13 zfs + boot partition Mediasize 64K

On Thu, Feb 11, 2021 at 05:34:40PM -0700, Russell L. Carter wrote:
> Greetings,
> 
> I really want to jump from stable/12 to stable/13 but one thing is
> causing a hesitancy.  And that is, my main raidz2 system has
> a system boot zfs mirror pair that has boot partition size
> (Mediasize) of 64K, and when I tried to zpool upgrade that pool a
> year or 2 ago I got some scary message something like "boot
> partition size is not large enough".  I asked about this on the
> lists but never received an answer.  So, laziness required me
> to ignore the problem and not zpool upgrade any of my 15 or so
> zpools in the interim.
> 
> A few weeks ago I tried to make buildworld/installworld upgrade
> 12->13 but the boot failed in the mounting filesystems phase with it
> couldn't find a bootable target.  So after restoring 12 I decided
> to wait a bit.  In the interim I have upgraded every zpool but that
> one system pool.  All the other freebsd-boot partitions have a size
> of 512K.
> 
> So what is the current advice?  Is a freebsd-boot partition size
> of 64K laughably obsolete, and I should get with the program and
> repartition those disks, or can I march blindly into the upgrade?
> 
> I guess I just want to understand where these sizes are going in
> the future.

Most layouts put a swap partition after the boot partition.  If
that is the case for you also, if you can disable the swapping to the
swap partition you can probably increase boot and reduce swap size
pretty easily.  Otherwise you're probably going to have to split
the mirror, repartition one drive, rebuild the mirror, reboot onto
that drive and then do the same to the other drive.  I've done it
before on a headless system in a remote DC.  With planning it's
perfectly doable.  I think I built a test vm in VirtualBox and
made sure it all worked on that before trying it for real.

Regards,

Gary