!ozoned@lemmy.world

This is an amazing article for folks interested in the low level IPC dbus. systemd, network manager, and or applications are leveraging dbus and with the new dbusbroker I expect more and more applications leverage it. It’s MASSIVELY confusing at first, but this is such a great article I hope it helps anyone interested in thr low level communications of userspace level linux applications.

Linux Cast: https://tilvids.com/c/thelinuxcast_channel/videos

Chris Were: https://share.tube/c/chrisweredigital/videos

Veronica Explains: https://tilvids.com/c/veronicaexplains_channel/videos

Techlore: https://neat.tube/c/techlore/videos

Linux Lounge: https://tilvids.com/c/linux_lounge/videos

Nicco’s videos mentioned in the article: https://tube.kockatoo.org/c/niccolo_ve/videos

FYI: I’m linking to their home location, but you can follow them from any Peertube instance. I’m on Tilvids and follow all of these folks from there so I don’t have to jump around to multiple places.

Coukd it also be that he used to work for them and is just familiar with it?

https://canonical.com/blog/author/popey

According to OSM, they’re complementary and they kind of work together:

https://blog.openstreetmap.org/2022/12/22/views-from-the-openstreetmap-foundation-on-the-launch-of-overture/

Please NEVER stop asking questions. As other have said, there really are no stupid questions.

If someone else acts like it’s a stupid question, then it’s their issue and not yours. NOTHING is easy until you understand it. The only way to understand it is to ask questions.

I’ve told numerous folks at work that before they do something if they have a question then let me know, because I’d rather answer a question then spend an hour or more fixing something broken.

I ask a LOT of questions. So many questions that when I first started in IT I had a lead that got used to me being in the office 2 hours before him so he knew I’d have a million questions and before he’d even go to his desk he’d stop by mine and ask if I had questions, which I always did.

Please please please please please ASK QUESTIONS.

I have been in IT for 12 years now, I have been on Linux for 16. Before this post I literally was in another thread and asked about BTRFS. I looked it up and it wasn’t making sense to me, so I asked a question. You can NEVER know EVERYTHING. And when you start to get comfortable that’s when something new comes out or you start digging deeper and have more.

Also anyone know if JustALinuxGuy is on Fediverse/Mastodon or a way to reach them about uploading these incredibly instructive videos to Peertube such as TILVids?

Question about the video. I’ve never used btrfs or Timeshift, so maybe this is just a thing with them, when he jumps to the CLI and unmounts, remounts RW, changes the @rootfs @, adds a dir and then mounts the subvolume on /dev/sda2 to /target.

This is totally new to me and I was wondering if anyone had an explanation as to why this was necessary?

I’m used to EXT4 and that’s what I run. But if BTRFS has FINALLY gotten stable and usable and I can take snapshots and roll back to older ones, kind of like branches in ostree, then maybe it’s worth this little extra work.

From what I find subvols are their own isolated branch with their own hierarchy. Is this how they’re meant to be used? Manually creating them and mounting/unmounting?

Debian

As an end user, unless you’re running a server, then no you shouldn’t have to mess with any of it.

If you’re running a server or a sysadmin you absolutely 100% should be paying attention. Almost every single vendor I’ve seen selling their applications only have initscripts. Which then cause issues. I’ve gone to the vendors and told them and they’ve said go to Red Hat. Well Red Hat doesn’t support that vendor’s init scripts.

Not naming an application, but it was from a BIG BLUE company and they said their only instructions are to call their script from the user. But it won’t remain running if you do that because systemd will close out the slice when the user logs out. SO it’s obvious they haven’t tried what they’re suggesting.

And I’m not attempting to state that systemd is impressive in any way. systemd basically took what had been building over 40 years of init scripting and threw it out the window and said our way is better. I don’t think it is. I’m just saying, with a directive based unit file it’ll be simpler to parse than a bash script.

Ok, so I have a very unique background in systemd. I worked at Red Hat supporting it basically as the primary support and I’ve worked with the developers of systemd at Red Hat directly. I no longer work there.

So first off, it’s “systemd” all lower case. I don’t care, but for some reason Lennart Pottering (creator) does.

systemd was a MASSIVE change. And Red Hat did a TERRIBLE job relaying it. To the point where I’m still trying to get my company to understand that it can NOT be treated like the old init systems. You can NOT just drop an init script in place and walk away and hope it works. Because a LOT of times it doesn’t. Due to forks, switch users, etc.

systemd is NOT an init system. RHEL 5 and older had sysvinit as it’s init systemd. RHEL 6 had UpStart as it’s init system and looked exactly like sysvinit that no one even noticed. systemd again is NOT an init system. Init system is 1 part of systemd. systemd does a lot of cool things. It bundles applications together, it manages those applications and can restart them or kill children, it can do resource constraints, it separates out users from the system, and lots more.

Because it is not an init system there is a LOT LOT LOT of bad recommendations out on the internet where someone has X problem and person suggests Y and IT WORKS! … except it doesn’t REALLY work as far as systemd is concerned and you’ll hit other issues or your application takes longer to start or stop and people just blame systemd.

It is systemd’s fault that it has done an ATROCIOUS job of helping people adapt. It’s a great example of RTFM. systemd’s man pages are INCREDIBLE and extensive, but when you drop so much knowledge it becomes more difficult to find what you want/need. systemd.index and systemd.directives are your best bet.

So systemd does a lot of amazing things that sysvinit never attempted to do. It’s never attempted to explain anything it expects everyone just learn magically. it’s INCREDIBLY complex, but once you understand it’s basics you can more easily get an application running, but as soon as there’s a problem it’ll just break your brain.

To give you an example, sshd’s old init script is like 250 lines of bash. systemd’s unit file comparative is like 12. Because systemd handles a LOT of what you manually had to handle before. BUT to get to that 12 you literally have to learn EVERYTHING new.

There is no “is it good or bad” here really imo. It’s a completely different fundamental design. Red Hat made it for themselves. Other distros picked it up. It can be argued that lots of folks followed Debian and Debian had a few Red Hat board members that were pushing it. Whether they pushed it of their own accord or because they were with Red Hat I don’t have a clue.

What I can say is at my current company they’re suffering from a LOT of systemd issues and they don’t even realize it. I’ve been working with Red Hat to try to get Insights to alert people to the failures and we’re making progress.

To see if you have issues just to start run the two following commands:

# systemctl list-units --failed
# systemd-cgls

If you have any units that are failed, investigate those. If you don’t need them, disable them. As for the systemd-cgls this shows HOW systemd is grouping things. ANY application that runs as a service (or daemon or application or runs in the background or however you wanna say it) should be under system.slice. ONLY humans logging into the system (meat bags NOT applications switching to users) should be in user.slice. A LOT of times what happens is an old init script is dropped in place, they start it, it has a switch user and systemd assumes it’s a user and puts it into user.slice. systemd does NOT treat anything in user.slice the same as in system.slice and this WILL eventually cause problems.

So again, is it good or bad? Eh. It does a lot of cool things, but they did a MASSIVE disservice to ALL of us by just expecting to relearn absolutely EVERYTHING.

Outside of Firefox, and very niche browsers, every other browser is built on Chromium. Edge, Opera, Chrome, etc. They all just add in their own customizations and things. You have to go look directly for Chromium, which the vast majority of the world doesn’t know exist. That’s the only reason why.

• Jellyfin - Media streaming type app - basically use it for movies/shows and pictures.
• Joplin - Note taking app
• Syncthing - Sync for phones to PC for backing up pictures
• Miniflux - RSS reader
• Minetest - FOSS Minecraft voxel engine
• Veloren - FOSS Cubeworld game written in Rust
• GoToSocial - Microblogging server - aka Twitter/Mastodon
• Semaphore - Frontend for GoToSocial
• SearXNG - Search engine
• Conduit - Matrix server - chat
• Libremdb - IMBD frontend
• Invidious - Youtube frontend
• Nitter - Twitter frontend
• Libreddit - Reddit frontend
• Rimgo - Imgur frontend
• Proxitok - TikTok frontend

Failed to get working:

• Mobilizon - FB groups type alternative
• Peertube - YT alternative on the Fediverse
• Lemmy - Tried for a day and just couldn’t get it working. Found out there are issues with Rocky Linux and Lemmy that broke about two months ago but no further work was done it. I’ll try again someday.