Date: Wed, 2 Jan 2013 15:05:57 -0500 From: Paul Mather <paul@gromit.homeunix.org> To: Matthew Seaman <m.seaman@infracaninophile.co.uk> Cc: stable@freebsd.org Subject: Re: Upgrade of RELENG_8 ZFS boot pool leads to unbootable system Message-ID: <330FFDAC-7162-4758-8CBA-343BD3644A27@gromit.homeunix.org> In-Reply-To: <50E48610.2040204@infracaninophile.co.uk> References: <FA810100-4041-40D7-AE09-77E07C1E3206@gromit.homeunix.org> <50E48610.2040204@infracaninophile.co.uk>
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On Jan 2, 2013, at 2:10 PM, Matthew Seaman =
<m.seaman@infracaninophile.co.uk> wrote:
> On 02/01/2013 17:49, Paul Mather wrote:
>> Yesterday, I updated my RELENG_8 ZFS-only system that has worked like =
a champ for ages. After a successful install{kernel,world} and reboot, =
I noticed the 20121130 entry in /usr/src/UPDATING and upgraded my ZFS =
pool via "zfs upgrade -a". I also upgraded my boot blocks as requested, =
and as per the "ZFS notes" section of /usr/src/UPDATING.
>>=20
>> Unfortunately rebooting with the upgraded pool failed. The =
"windmill" boot spinner spins for a tiny amount of time and then stops =
dead. :-( I don't get to the boot loader menu at all.
>>=20
>> I downloaded a very recent RELENG_8 snapshot =
(FreeBSD-8.3-RELENG_8-r244923-JPSNAP-amd64-amd64-memstick.img) from =
pub.allbsd.org and was able to boot successfully from USB using that. I =
entered Fixit Mode and tried to write the boot blocks on the memstick =
image onto my hard drives but the resultant system still wouldn't boot. =
The commands I used (from Fixit Mode) are these:
>>=20
>> gpart bootcode -b /dist/boot/pmbr -p /dist/boot/gptzfsboot -i 1 =
ad4
>> gpart bootcode -b /dist/boot/pmbr -p /dist/boot/gptzfsboot -i 1 =
ad6
>>=20
>> (ad4 and ad6 are my two hard drives.)
>>=20
>> If I "load zfs" before booting the USB memstick then I can see my old =
pool listed when I do "zfs import". I haven't tried importing the pool =
because I'm not sure if that would make the problem worse.
>>=20
>> Does anyone have any advice in restoring this system to bootability? =
I followed the standard "root on ZFS" recipe using a two drive mirror =
when installing the system initially. Each drive uses GPT with three =
partitions: freebsd-boot, freebsd-swap, and freebsd-zfs in that order. =
Like I said at the start, all this worked for a long time until just now =
when I upgraded the pool to enable "feature flags" support. :-(
>>=20
>> Any help is appreciated.
>=20
> I think you may be running into problems with zpool.cache. This has
> been fixed in current, which now has the ability to find the root =
zpool
> without a valid zpool.cache, but that I suspect is faint comfort for =
you.
>=20
> To recover from a toasted zpool.cache, you need to boot from alternate
> media and then import your root zpool. It's easiest to do that to a
> temporary directory. The important bit is to copy the zpool.cache =
onto
> your actual zroot device:
>=20
> -- Boot from install media to 'Live CD' and log in as root (no =
password)
Given the above, does this need to be a -CURRENT Live CD? I've been =
using the RELENG_8 snapshot memstick.img mentioned in my original =
message above.
>=20
> # kldload zfs -- should load opensolaris.ko =
automatically
> # cd /tmp -- this should be a writable MFS; you'll
> need to arrange something similar if
> not.
> # zpool import -o cachefile=3D/tmp/zpool.cache -R /tmp/zroot zroot
> -- this should create a zpool.cache file
I tried this and it complained about the pool being in use by another =
system---the original system that won't boot any more. I expected this, =
and added "-f" to force an import.
> # cp zpool.cache /tmp/zroot/boot/zfs/
This part also failed for me. My "zroot" fileset has a mountpoint =
property set to "legacy". I had to mount this manually, via "mount -t =
zfs zroot /tmp/zroot" to make the /tmp/zroot/boot/zfs directory =
accessible.
> # zfs umount -a
> # shutdown -r
>=20
> Eject the install media, and the system should boot up from your root =
spool.
Unfortunately, it didn't boot from the root pool. I get the same thing =
happening: the "windmill" spins for a very short time and then stops =
dead. I don't even make it to the "BTX Loader" output, let alone the =
boot loader menu options. :-(
Thank you for the suggestions.
Cheers,
Paul.
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