Description of problem: We'd like the ability to define mount units on the kernel command line. This allows the system to be booted into a snapshot of the system state (for e.g. using LVM2 CoW or thin provisioned snapshots) and enables rollback for system updates by allowing the administrator to preserve a copy of the prior system state and to optionally roll the system back to that state at a later time using the snapshot merge facility. This would add new kernel command line syntax something like the following: systemd.mount=what:where:fstype:options The feature has been proposed to upstream systemd and has received some initial positive comments: https://github.com/systemd/systemd/issues/27260 The new functionality would be added to the existing systemd-fstab-generator to write out mount units during early boot. Version-Release number of selected component (if applicable): systemd-250-12.el9_1 How reproducible: 100% Steps to Reproduce: 1. man systemd-fstab-generator Actual results: No syntax exists for specifying kernel command line mount units. Expected results: The ability to specify mount units on the kernel command line Additional info: This will be used by Leapp and boom to provide rollback capable upgrades.
There are two additional pull requests for this feature that were merged for v254: fstab-generator: fixes for systemd.mount-extra= https://github.com/systemd/systemd/pull/28518 fstab-generator: enable fsck for block device mounts specified in sys… https://github.com/systemd/systemd/pull/28544