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

[John Covici]

On Tue, 28 May 2019 15:58:06 -0400,
Tsukasa Mcp_Reznor wrote:
>
>
>
> ________________________________________
> From: Rich Freeman <rich0@g.o>
> Sent: Tuesday, May 28, 2019 9:54 AM
> To: gentoo-user@l.g.o
> Subject: Re: [gentoo-user] block for zfs-0.8.0 how to fix safely
>
> 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
>
>
>
> I have upgraded to zfs-0.8.0 while downgrading the kernel on my server to 4.19.45 to avoid the performance hit involved with encryption.
>
> Steps I took that seemed to work well.
> 1. add >=sys-kernel/gentoo-sources-5.0 to package.mask
> 2. emerge gentoo-sources-4.19.45 (auto picked just doing a normal emerge -av gentoo-sources)
> 3. eselect kernel list/set to set the symlink for /usr/src/linux
> 4. emerge -C sys-kernel/spl (it doesn't remove old installs in kernel modules for previous kernels that I've seen)
> 5. enter /usr/src/linux and do your standard make -j(x) && make modules_install && make install && update bootloader etc
> 6. manually emerge -auv zfs to get 0.8.0 pulled in and built (if you have other modules you can consider doing emerge -av @module-rebuild afterwards)
> 7. reboot and test it out :)
> 8. if everything is fine and running well, and you are positive you are not going to be going back to <0.8.0 you can do zpool upgrade -a, to take advantage of the new features of 0.8.0

Thanks, but does not 4.19.45 have the patches for the new
vulnerabilities of intel chips back ported?  You would they would have
done that.

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici wb2una
         covici@××××××××××.com