on solaris systems when you start a system update, there's a boot environment that gets created automatically and in the boot menu you can select the one you want. This makes it easy to boot to boot a previous system if an update introduced a bug for example. You can also go back to the latest version if you need to.
It doesn't happen too often but once in a while, a yum update will break the system and then you have to spend time trying to fix it with yum history and such only to give up and reinstall everything either from backup or scratch.
I read that on opensuse, they have a system called snapper with btrfs, on fedora 33 they also introduced btrfs snapshots. Eventually ubuntu will have zsys with zfs, snapper might also work I haven't explored it.
Is there something similar with RedHat and variants? I know RHEL dropped btrfs support some time ago so it's not possible to partition with that. ZFS will probably never happen. Stratis is a technology preview I think.
LVM feels old and quirky. Thanks for introducing me to ssm, that at least made creating LVM partition easier. There's at least 2 things I don't like about LVM:
- You have to specify the size of the snapshot, otherwise you get a warning every single time. That doesn't give me confidence that those snapshots can stay around for a long time.
- If you want to go back to the previous system, you have to merge the snapshot and then you lose it,
I know there's a tool called boom that helps boot from snapshots but it looks half baked. I still have to do a manual lvm snapshot, then create a grub entry with boom.
Is there an easy reliable way to protect your root filesystem before doing an update?
Thanks for pointers.