Boot loader stuck after first stage upgrading 11.2 to 12.0-RC2

[Mark Martinec]

2019-12-10 16:35, Marc Branchaud wrote:

> On 2019-12-10 9:18 a.m., Mark Martinec wrote:
>> Commenting on a thread from 2018-12 and from 2019-09-20, with my 
>> solution
>> to the boot problem at the end, in case anyone is still interested.
> 
> Thank you very much for this.  A couple of questions:
> 
> (1) Why do you say "raw devices for historical reasons"?  Glancing
> through the zpool man page and the Handbook, I see nothing
> recommending or requiring GPT partitions.

Apparently using raw devices for zpool is now discouraged,
although I don't think it has ever become officially unsupported.


> (2) Just to be 100% clear, my 11.3 non-root zpool looks like this:
>         NAME        STATE     READ WRITE CKSUM
>         storage     ONLINE       0     0     0
>           raidz2-0  ONLINE       0     0     0
>             ada2    ONLINE       0     0     0
>             ada3    ONLINE       0     0     0
>             ada4    ONLINE       0     0     0
>             ada5    ONLINE       0     0     0
>             ada6    ONLINE       0     0     0
>             ada7    ONLINE       0     0     0
> 
> So this is using raw devices.  Are you saying that if I upgrade this
> machine to 12 that it won't be able to boot?

It is possible it won't boot under 12, although not necessary.

Try booting from a 12.0 (or 12.0) memory stick - it that boots,
it is probably a safe bet that it will survive an upgrade.

Of the bunch of machines that I have upgraded from 11.2 to 12,
only three failed to boot under 12.0 loader. There were a couple
of others which upgraded and booted fine even though they
had a zfs pool on raw devices. I never had a problem of
booting on hosts that had zfs pool on a gpt partition.

So it's a lottery: a few raw devices in a zpool seem to do fine,
while many raw devices in a zpool is asking for trouble
under 12.0 and later.

   Mark