[systemd-devel] the need for a discoverable sub-volumes specification

[Chris Murphy]

On Thu, Nov 18, 2021 at 2:51 PM Chris Murphy <lists at colorremedies.com> wrote:
>
> How to do swapfiles?
>
> Currently I'm creating a "swap" subvolume in the top-level of the file
> system and /etc/fstab looks like this
>
> UUID=$FSUUID    /var/swap               btrfs   noatime,subvol=swap 0 0
> /var/swap/swapfile1 none swap defaults 0 0
>
> This seems to work reliably after hundreds of boots.
>
> a. Is this naming convention for the subvolume adequate? Seems like it
> can just be "swap" because the GPT method is just a single partition
> type GUID that's shared by multiboot Linux setups, i.e. not arch or
> distro specific
> b. Is the mount point, /var/swap, OK?
> c. What should the additional naming convention be for the swapfile
> itself so swapon happens automatically?

Actually I'm thinking of something different suddenly... because
without user ownership of swapfiles, and instead systemd having domain
over this, it's perhaps more like:

/x-systemd.auto/swap -> /run/systemd/swap

And then systemd just manages the files in that directory per policy,
e.g. do on demand creation of swapfiles with variable size increments,
as well as cleanup.


-- 
Chris Murphy