Technical Spec, better upgrade/rollback control

[Richard Hughes]

On 21 February 2014 05:46, Chris Murphy <lists at colorremedies.com> wrote:
> I'm aware of three possible candidates for implementing snapshots and rollbacks:

Yes, sorry about this, I have an email I've been meaning to send you
for a few weeks now.

> LVM Thin Provisioning

Now the kernel doesn't explode when thinp runs out of physical space
I'm happier considering this.

> b.) Snapper: Lists a dependency on either LVM Thin Provisioning, or Btrfs. Snapper+Btrfs is the most mature and actively maintained option at this time. It's presently used in openSUSE, by default when the file system is Btrfs, for at least a couple of years.
> https://github.com/openSUSE/snapper/blob/master/README
> http://snapper.io/
> http://snapper.io/faq.html

I helped package snapper in Fedora and have been using it on and off
for a few months on btrfs. btrfs has been stable for me, but suffers
hugely when trying to use a VM on top of it without chattr +C.

> c. ) Gnome: Richard Hughes has expressed interest in making this happen within Gnome. As far as I know it doesn't yet exist, but is expected to depend on either Btrfs or LVM Thin Provisioning snapshots.

I was intending to use snapper, but the real problems lie as we also
want to snapshot /boot, might not want LVM/btrfs for
performance/stability reasons, and that we actually want some things
to be excluded from the snapshot, e.g. the systemd journal. I'm really
open for ideas here, as you know much more about all this than me.
Thanks.

Richard.