Silverblue and Kinoite will have /var on its own Btrfs subvolume
Silverblue and Kinoite: For new clean automatic (guided) installations, create a "var" subvolume to be mounted at /var.
- Name: Chris Murphy
- Email: email@example.com
- Targeted release: Fedora Linux 36
- Last updated: 2022-02-09
- devel thread
- FESCo issue: #2742
- Tracker bug: #2051550
- Release notes tracker: #803
Currently, Silverblue and Kinoite mimic other Fedora desktops. There is a "root" subvolume mounted at
/ and a "home" subvolume mounted at
This proposal adds a "var" subvolume to be mounted at
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 can be independently snapshot and rolled back from the "root" subvolume, which contains
- The ability to snapshot "var" and use Btrfs send/receive to replicate only "var" permits for an efficient way of backing up the variable system data, similar to snapshotting "home" and replicating it as a way of backing up user data.
- A clean install will 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, or a favorite backup utility.
- Proposal owners:
- change anaconda Silverblue and Kinoite profiles, such that automatic/guided installation creates a "var" subvolume mounted at /var.
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
/etc/fstabfor an explicitly listed
- The change won't generally be noticeable to users
- Users will see an additional
/varmount point in /etc/fstab, and
- 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.
- Contingency deadline: beta freeze (not a System Wide Change)
- Blocks release? No
No significant documentation is planned other than this change proposal.
N/A (not a System Wide Change)