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A quick look into systemd reveals that it's comprised of multiple components. For example the journal service is a separate daemon. What part of this does not a

A quick look into systemd reveals that it's comprised of multiple components. For example the journal service is a separate daemon. What part of this does not align with your vision? EDIT: looks like the "monolithic" myth has already been busted: http://0pointer.de/blog/projects/the-biggest-myths.html http://0pointer.de/blog/projects/the-biggest-myths.html I would say the distinction between systemd and older systems is that systemd follows the "better is better" mantra of design, while older systems follow the "worse is better" mantra of design. Older systems often feel like quick hacks. For example SysV init is a collection of init scripts. Yeah it is "simple" in that the init service itself is simple, but writing the scripts themselves is anything but simple, and they are brittle as well. How often have you seen init scripts failing during startup or boot? And why must you write daemon management code over and over again your init scripts? All this does is pushing complexity out of the init service and into the scripts. Systemd is taking complexity upon itself so that the scripts can be simple.

Tobu 13y ago
It's monolithic because you can't pick and choose the components. You have to use all of systemd, or none of it. You can't replace bits of it, or use just parts of it.
- FooBarWidget 13y ago
  And how exactly does Xorg allow you to use parts of it? More importantly, what parts of systemd do you not want to use or do you want to replace, and why? EDIT: what you're saying appears to be untrue. According to http://0pointer.de/blog/projects/the-biggest-myths.html http://0pointer.de/blog/projects/the-biggest-myths.html, they provide configure switches for enabling or disabling many things, not unlike how the Linux kernel allows you to enable or disable features. You know, there are so many people here bashing on Lennart, I'm wondering whether any of you have done your homework at all or because you just bash Lennart for the sake of it. I'm not even using systemd and I found these things in 5 minutes.
  - DASD 13y ago
    I'd like to not use udev. I have a custom Linux that runs both on standardized(internally defined) servers and also virtualized(known hardware) servers. As such, I'm well under 900ms boot times that systemd mentions by using SysV init. But the systemd project does not accept patches (http://freedesktop.org/wiki/Software/systemd/MinimalBuilds/ http://freedesktop.org/wiki/Software/systemd/MinimalBuilds/) to disable what is considered a core component.
    - FooBarWidget 13y ago
      Alright, point taken. Then systemd is not for you. However I want to argue that not all software should cater to everybody. While modularity (which in this discussion is apparently defined as "the ability to disable or swap components") is often seen as a good thing, there are quite a lot of downsides as well: - Certain guarantees and consistencies disappear. Instead of having a system that you know you can rely on, it suddenly becomes entirely dependent on the configuration options. While it sounds nice if any part can be enabled, disabled, moved or swapped, then the system's predictability goes down. Furthermore, some combinations may be incompatible because abstractions are inherently leaky. Good luck finding out whether you're suffering from a compatibility problem or not. You can compare this to the many complaints about Android fragmentation. Because everybody can customize Android, writing an app that works on all Android devices becomes extremely difficult. - Installation complexity goes way up. It's much easier to install a system if it states "I need this, this and this", instead of "I can use this, or this, or this, if it's configured in X, Y and Z way". - Certain features cannot be implemented in a simple manner because you have to cater to the lowest common denominator. XFree86 was like that. Because it had to be portable, it cannot assume any kernel capabilities. And as a result XFree86 came with its own mode setting code, its own ELF binary loader, had to run as root, etc etc.
      - vertex-four 13y ago
        > However I want to argue that not all software should cater to everybody. The issue here is that the Linux kernel developers are starting to make decisions that assume systemd is being used. For example, the (proposed?) new cgroups API is being built with the idea that systemd will manage it, and anything else that wants to interact with it will go through systemd.
- zanny 13y ago
  Ubuntu just started using logind in 13.04, but haven't adopted the rest of systemd. Some parts (journal, systemd core, udev) can't be detached, but a lot of the peripheral software outside the init -> maintain services -> log events process are optional.
  - Tobu 13y ago
    Ubuntu is splitting logind from systemd with no help from the systemd maintainers, because some gnome projects have started requiring logind. That effort is spent undoing Lennart's work swallowing most of the consolekit code base into systemd. The systemd maintainers won't accept patches that make logind a separate project again.
    - teho 13y ago
      systemd-logind doesn't use code from consolekit. It has been written from scratch. ConsoleKit itself has been unmaintained for a long time.
- teho 13y ago
  >You can't replace bits of it, or use just parts of it. You can replace pretty much everything. You need only systemd, systemd-udev and systemd-journald. Virtually everything else is optional. It also allows you to use syslog with journald. It allows you use use crond instead of the timer units. You could use ConsoleKit instead of systemd-logind as session manager... and so on and so forth.
asb 13y ago
I agre with your final paragraph and I rather like the consolidation that systemd offers. I'm certainly not going to miss fiddling with consolekit and I'm looking forwards to managing my user session via systemd. It reduces the number of things I need to learn to have a decent level of control over my system.

Tobu 13y ago

It's monolithic because you can't pick and choose the components. You have to use all of systemd, or none of it. You can't replace bits of it, or use just parts of it.

FooBarWidget 13y ago
And how exactly does Xorg allow you to use parts of it? More importantly, what parts of systemd do you not want to use or do you want to replace, and why? EDIT: what you're saying appears to be untrue. According to http://0pointer.de/blog/projects/the-biggest-myths.html http://0pointer.de/blog/projects/the-biggest-myths.html, they provide configure switches for enabling or disabling many things, not unlike how the Linux kernel allows you to enable or disable features. You know, there are so many people here bashing on Lennart, I'm wondering whether any of you have done your homework at all or because you just bash Lennart for the sake of it. I'm not even using systemd and I found these things in 5 minutes.
- DASD 13y ago
  I'd like to not use udev. I have a custom Linux that runs both on standardized(internally defined) servers and also virtualized(known hardware) servers. As such, I'm well under 900ms boot times that systemd mentions by using SysV init. But the systemd project does not accept patches (http://freedesktop.org/wiki/Software/systemd/MinimalBuilds/ http://freedesktop.org/wiki/Software/systemd/MinimalBuilds/) to disable what is considered a core component.
  - FooBarWidget 13y ago
    Alright, point taken. Then systemd is not for you. However I want to argue that not all software should cater to everybody. While modularity (which in this discussion is apparently defined as "the ability to disable or swap components") is often seen as a good thing, there are quite a lot of downsides as well: - Certain guarantees and consistencies disappear. Instead of having a system that you know you can rely on, it suddenly becomes entirely dependent on the configuration options. While it sounds nice if any part can be enabled, disabled, moved or swapped, then the system's predictability goes down. Furthermore, some combinations may be incompatible because abstractions are inherently leaky. Good luck finding out whether you're suffering from a compatibility problem or not. You can compare this to the many complaints about Android fragmentation. Because everybody can customize Android, writing an app that works on all Android devices becomes extremely difficult. - Installation complexity goes way up. It's much easier to install a system if it states "I need this, this and this", instead of "I can use this, or this, or this, if it's configured in X, Y and Z way". - Certain features cannot be implemented in a simple manner because you have to cater to the lowest common denominator. XFree86 was like that. Because it had to be portable, it cannot assume any kernel capabilities. And as a result XFree86 came with its own mode setting code, its own ELF binary loader, had to run as root, etc etc.
    - vertex-four 13y ago
      > However I want to argue that not all software should cater to everybody. The issue here is that the Linux kernel developers are starting to make decisions that assume systemd is being used. For example, the (proposed?) new cgroups API is being built with the idea that systemd will manage it, and anything else that wants to interact with it will go through systemd.
zanny 13y ago
Ubuntu just started using logind in 13.04, but haven't adopted the rest of systemd. Some parts (journal, systemd core, udev) can't be detached, but a lot of the peripheral software outside the init -> maintain services -> log events process are optional.
- Tobu 13y ago
  Ubuntu is splitting logind from systemd with no help from the systemd maintainers, because some gnome projects have started requiring logind. That effort is spent undoing Lennart's work swallowing most of the consolekit code base into systemd. The systemd maintainers won't accept patches that make logind a separate project again.
  - teho 13y ago
    systemd-logind doesn't use code from consolekit. It has been written from scratch. ConsoleKit itself has been unmaintained for a long time.
teho 13y ago
>You can't replace bits of it, or use just parts of it. You can replace pretty much everything. You need only systemd, systemd-udev and systemd-journald. Virtually everything else is optional. It also allows you to use syslog with journald. It allows you use use crond instead of the timer units. You could use ConsoleKit instead of systemd-logind as session manager... and so on and so forth.

asb 13y ago

I agre with your final paragraph and I rather like the consolidation that systemd offers. I'm certainly not going to miss fiddling with consolekit and I'm looking forwards to managing my user session via systemd. It reduces the number of things I need to learn to have a decent level of control over my system.