[systemd-devel] 'Offline System Updates' examination

[Lennart Poettering]

On Thu, 21.06.12 17:31, Alexander E. Patrakov (patrakov at gmail.com) wrote:

> 1) Can one configure the system to use kexec instead of the reboot?
> (BTW, the only machine that I have access to and where kexec doesn't
> work is a multi-CPU KVM guest)

Well, it doesn't really matter how you reboot, as long as you do it
somehow.

Well, and actually, if people decide not to reboot at all it's OK too i
guess, "systemctl isolate system-update.target" should work
too. However, I'd always recommend rebooting first, so that the system
is in a really well defined state when the update is attempted.

> 2) Did anyone consider a plan to do updates on ext4 and btrfs
> differently? E.g. one can use the same sequence as above for ext4 and
> "make a writable snapshot, install to snapshot, reboot with that
> snapshot as root" on btrfs. This, theoretically, has a huge advantage
> of being able to work on on source-based distributions like gentoo
> (unlike the original sequence, which means at least 1 hour of complete
> downtime due to compilation of LibreOffice at step 3).

If source based distros want to implement this I'd probably recommend
them to compile everything in the system, and only do the final step,
the installation as part of the system-update step.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.