systemd 248 RC1 Released With New "System Extension Images" Concept

[piotr.dobrogost]

Can't keep up with the pace of systemd development I think I am going to move slowly on BSD the majority of my computers...

Wait, do any of BSDs support your beloved init system freedom?

[jacob]

That's precisely what fstab is for.

Which just goes to show that you missed the point completely.

How do you create new persistent mount points programmatically (= not by manually editing a file)? You can't.
How do you modify mount options programmatically (=not with grep/sed/awk)? You can't.
How do you ensure that something gets mounted if and only if the required resource (volume, network share etc.) is available and kicking? You can't.
How can users automatically mount an overlay or custom extension upon login in a private namespace? They can't.
How do you find *programmatically* (= not with "grep /var/log/...") which mounts have failed and why? You can't.
Etc...

Like most things in *nix, fstab is a vomitous kludge that has been hacked together with no foresight, no care for consistency or usability (other than by a script-happy sysadmin), no sane or predictable syntax and no unifying vision of how the OS should work as a whole. It's in urgent need of dying its ignominious death.

[Danielsan]

Wait, do any of BSDs support your beloved init system freedom?

I don't think but so far BSD systems are following a different path...

[sjukfan]

Whenever I'm unsure of the reason behind a systemd function I think of it in a mobile phone. System extension images can probably be used both as an install media for factory reset, and maybe for apps too.

[jacob]

Yeah, interesting, but I don't see these technologies coming to fruition. This is a new thing, but I bet we will never see a Linux distro capable of dynamically plug/unplug programs. People that have used Slax know what I mean.

You have a read-only "extension image". You double click on it and voilà, it merges with the root fs.

Also it is not clear how they will implement configuration of these "extension images" applications. The devs stated that /etc is off-limits. Will the configs be put in /usr/local/etc?? But I suppose this will require patching a bunch of programs that currently use /etc to store their config.

p.s. I am one of those people playing with overlayfs. I have settled on a "live" setup, with the rootfs mounted ro from a squashfs and the overlay in tmpfs. To maintain persistence for some programs, I use containers ( through systemd-nspawn ). So I have a base system that is ro and overlay in tmpfs and programs needing to "have memory" in containers on another volume ( a xfs one for various reasons ).

It may not have come to fruition under Slax because Slax has never been mainstream enough for it to gain any critical mass. But incorporation in systemd means that it will immediately become natively supported in RH/Fedora, Ubuntu, Debian, SUSE and Arch (and their respective derivatives) which is a different story altogether. Also Fedora Silverblue is already going in that general direction, so I wouldn't dismiss it.

[RahulSundaram]

That's precisely what fstab is for.

No, fstab is just a static list of mounts. I would start by reading

https://www.freedesktop.org/software/systemd/man/systemd-sysext.html

When you want to do runtime dynamic changes, fstab doesn't help at all

[Shiba]

No, fstab is just a static list of mounts. I would start by reading

https://www.freedesktop.org/software/systemd/man/systemd-sysext.html

When you want to do runtime dynamic changes, fstab doesn't help at all

If you want dynamic changes you craft a custom fstab file and load that.

*programmatically*

I don't think you know what that word means.

[jacob]

If you want dynamic changes you craft a custom fstab file and load that.


I don't think you know what that word means.

I don't think you know much at all.

[RahulSundaram]

If you want dynamic changes you craft a custom fstab file and load that.

If you have to craft a custom fstab and load it yourself, that is not dynamic.

[Vistaus]

Dear Penthouse,

Met the girl of my dreams last night. We clicked instantly and the next thing you know we had an overlay on the couch. She tried to mount me on dining room table but it crashed. No problem, we started right back up fscked all night long. She really knew how to ctrl the system's d.

Yours truly,
Linux Guy

Nice!