dracut.cmdline(7): document overlay persistence requirements

[opk12]

do_live_overlay() in dmsquash-live-root.sh makes assumptions about persistence command-line arguments:

• rd.live.overlay's pathspec must start with /

because devspec is mounted on /run/initramfs/overlayfs and pathspec is expanded as /run/initramfs/overlayfs$pathspec. source

• the overlay image must contain directories named overlayfs and ovlwork

source

[ytrezq]

@opk12 : this is something I’m failing to understand.

What’s the directory structure for using persistant overlay alongside overlayfs ? Which device is mounted on /run/overlayfs

[FGrose]

/run/overlayfs is a symbolic link to /run/initramfs/overlayfs/overlayfs
and /run/ovlwork is a symbolic link to /run/initramfs/overlayfs/ovlwork

See

dracut/modules.d/90dmsquash-live/dmsquash-live-root.sh

Line 147 in 2293609

ln -s /run/initramfs/overlayfs/overlayfs /run/overlayfs$opt

[johannbg]

This issue is being marked as stale because it has not had any recent activity. It will be closed if no further activity occurs. If this is still an issue in the latest release of Dracut and you would like to keep it open please comment on this issue within the next 7 days. Thank you for your contributions.

[ytrezq]

@johannbg of course, this documentation problem should be solved. But I m not having much to add.

[opk12]

Could you please reopen, as the feature is unusable without knowledge of ovlwork and the fix is a couple words?

[rustydb]

Definitely could use some documentation, I've been in a rabbit hole with this for some time. I make the overlay file, mount it, make the two directories... but I see blocks of logic that seem like i should make a directory instead of an overlay file.
Just some comments at a base level to tell which if block matters for which part of the doc would be amazing... Not trying to make a huge ask.

[stale]

This issue is being marked as stale because it has not had any recent activity. It will be closed if no further activity occurs. If this is still an issue in the latest release of Dracut and you would like to keep it open please comment on this issue within the next 7 days. Thank you for your contributions.

[opk12]

This issue is being marked as stale because it has not had any recent activity. It will be closed if no further activity occurs. If this is still an issue in the latest release of Dracut and you would like to keep it open please comment on this issue within the next 7 days. Thank you for your contributions.

[stale]

This issue is being marked as stale because it has not had any recent activity. It will be closed if no further activity occurs. If this is still an issue in the latest release of Dracut and you would like to keep it open please comment on this issue within the next 7 days. Thank you for your contributions.

[johannbg]

.