Document how to use boot-to-snapshot and rollback?

[FroggyFlox]

Among the benefits from our rebase is the ability to use the "boot-to-snapshot" feature from openSUSE to rollback to a previous working system state thanks to Snapper.
While the feature is documented in openSUSE documentation, our users may be looking for documentation/help in our own documentation. As a result, it could be interesting to provide a step-by-step illustration (with screenshots) of the process, while still linking to the openSUSE documentation as the reference.

It may also be important to specify that not all directories are included in such snapshots, including /opt/, which thus implies that one cannot rollback Rockstor system files with this feature (if I'm correct).

@phillxnet, do you think it's a good idea?

[phillxnet]

@FroggyFlox I certainly do believe this is a good idea. Apologies fro completely neglecting this issue. It just came up again in the forum actually.

Just stopping by to add a link to the core issue we have open on this:
https://github.com/rockstor/rockstor-core

Good point re not all subvols are included. I believe that the /var dir is also not included which is hand for us actually as that is our postgres db store, meaning that we hopefully remain consistent re code/db over a rollback. I.e. the installed rockstor files and their associated db state remain in-step and unaffected by this rollback. I've not proven this yet thought.

[FroggyFlox]

Thanks for pointing to the rockstor-core issue: rockstor/rockstor-core#2166

I believe that the /var dir is also not included which is hand for us actually as that is our postgres db store, meaning that we hopefully remain consistent re code/db over a rollback. I.e. the installed rockstor files and their associated db state remain in-step and unaffected by this rollback. I've not proven this yet thought.

The full list of excluded dir is:
https://doc.opensuse.org/documentation/leap/reference/html/book-reference/cha-snapper.html#snapper-dir-excludes

• /boot/grub2/i386-pc, /boot/grub2/x86_64-efi, /boot/grub2/powerpc-ieee1275, /boot/grub2/s390x-emu
• /home
• /opt
• /srv
• /tmp
• /usr/local
• /var