https://fedoraproject.org/wiki/Changes/VarSubvol4SilverblueKinoite
== Summary ==
Silverblue and Kinoite: For new clean automatic (guided)
installations, create a "var" subvolume to be mounted at /var.
== Owner ==
* Name: [[User:chrismurphy| Chris Murphy]]
* Email: bugzilla(a)colorremedies.com
== Detailed Description ==
Currently, Silverblue and Kinoite mimic other Fedora desktops. There
is a "root" subvolume mounted at `/` and a "home" subvolume mounted
at
`/home`.
This proposal adds a "var" subvolume to be mounted at `/var`.
The "var" subvolume will be located at the top-level of the Btrfs file
system, along-side the "root" and "home" subvolumes. An entry in
`/etc/fstab` will mount it at `/var` during startup.
== Benefit to Fedora ==
Users who opt into Btrfs features like snapshots and rollbacks.
* By moving /var into its own subvolume, it will be excluded from
snapshots and rollbacks of the "root" subvolume, which contains `/etc`
and `/usr`.
* Users will find it straightforward to rollback "root" while not
rolling back "var": including logs, VMs, databases, flatpaks, etc.
* The ability to snapshot only "var" and use Btrfs send/receive to
replicate only "var" permits for an efficient way of backing up the
variable system data.
** A clean install can restore the "root", therefore it doesn't
strictly need to be backed up. Meanwhile "var" and "home" can be
restored using snapshot replication via send/receive.
== Scope ==
* Proposal owners:
** changes to lorax and anaconda as needed so that Silverblue and
Kinoite variants have their own installation kickstart, such that
automatic/guided installation automatically creates "var".
*** possible liability, determine whether the the addition of /var
mount point for Btrfs scheme results in /var mount point for other
schemes (and inhibit)
== Upgrade/compatibility impact ==
Change will not be applied to upgrades. But we can document steps to
apply the change to existing installations.
== How To Test ==
* Do a clean installation and check `df` and `/etc/fstab` for an
explicitly listed `/var` mount point.
== User Experience ==
* The change won't generally be noticeable to users
* Users will see an additional `/var` mount point in /etc/fstab, and `df`
* Some utilities, notably backup programs like borg backup, and rsync
with -x option, will treat Btrfs subvolumes as separate file systems
and may not descend (recursively) into them.
== Dependencies ==
* Anaconda/blivet, lorax, and possibly kickstarts
== Contingency Plan ==
* Contingency deadline: beta freeze
* Blocks release? No
== Documentation ==
No significant documentation is planned other than this change proposal.
== Release Notes ==
--
Ben Cotton
He / Him / His
Fedora Program Manager
Red Hat
TZ=America/Indiana/Indianapolis