Re: [gentoo-user] block for zfs-0.8.0 how to fix safely

[Rich Freeman]

On Tue, May 28, 2019 at 4:35 AM Neil Bothwick <neil@××××××××××.uk> wrote:
>
> On Tue, 28 May 2019 04:04:23 -0400, John Covici wrote:
>
> > In my latest update, there is a hard block sys-kernel/spl-0.7.13 is
> > blocking 0.8.0.  Can I unmerge the old one and still have access to my
> > pools while the new one is compiled.  My whole system except /boot is
> > on zfs, this is wny I am asking, or should I do this one emerge from a
> > rescue disk?
>
> spl is now part of the zfs package, so you will still have it after
> updating. During the update, the module will still be in memory. If you
> reboot during the update, you will have a problem, I kept a backup copy
> of the spl modules just in case, or you could quickpkg spl.

The one file you really need is:
/lib/modules/4.19.46/extra/spl/spl.ko.gz
(or whatever version you're using).

I would personally do the switch during a kernel update, so that you
can leave your old modules around and boot the old kernel.

I'm honestly not sure if portage will leave the old kernel module in
place when doing the switch.  Looking at my kernel directory I see old
spl modules so when re-emerging spl it isn't removing the old modules.
However, I also can't see any documented mechanism that would protect
kernel modules from unmerging.  It could be an undocumented portage
feature (it does make sense to leave the old kernel modules around).

If you update an existing kernel in-place none of this will help as
the zfs bundled spl would overwrite the spl-bundled version.  And of
course it wouldn't make sense to mix the two in a kernel anyway.

I'll see how it goes in a few months when I try out 0.8.  As much as
I'm looking forward to a few of its features I'm really in no rush to
go trying new versions of filesystems...

-- 
Rich