15 ms·

Cleaning an Arch Linux installation

101 points by ilpianista 11y ago

vamur 11y ago
My Archlinux based LiveUSB setup comes around to 1GB and has Libreoffice, Wine, Firefox/Chromium. That said, there are some questionable dependencies in Archlinux lately. For example, mpv now requires smbclient, which then pulls python2.7.
- RexRollman 11y ago
  There's always been little things like that. For example, installing Feh pulls in libid3tag (which for whatever reason is a dependency of imlib2).
  - leni536 11y ago
    Maybe for opening album art? Feh complains if I want to open an mp3 with embedded album art though: feh WARNING: 01.mp3 - No Imlib2 loader for that file format And imlib2 does depend on libid3tag.
    - RexRollman 11y ago
      I know but it's a weird dependency to me. One would think that an ID3 editor would need that, not the image processing utililty itself.
- plg 11y ago
  Is freeBSD better on this front?
  - andrers 11y ago
    Not really. I thought of installing gcc 5.1 through its binary package and it tried to install gcc-ecj 4.5 along with it. I ended up installing it through the ports system, disabling Java support. Its ports are where FreeBSD really shines. They're something in between Arch's ABS and Gentoo's portage. I just wish there was someway to say "install binutils via pkg, and only compile gcc itself".
    - floatboth 11y ago
      pkg install binutils && make -C/usr/ports/lang/gcc install clean :-) You can also `make package` to, well, make your own binary package (it will be in /usr/ports/lang/gcc/work/pkg) to distribute to other machines. Or use poudriere to setup a proper package build server.
- creshal 11y ago
  The dependencies are mainly insane upstream defaults, which Arch doesn't try to hide. For many packages there are modified PKGBUILDs available in the AUR for these situations (mplayer-nosmb, pidgin-mini, …). Sadly not for mpv (yet, I've been meaning for a while to make one, but didn't yet get around to it).
nextos 11y ago
I've always found Arch to be among the easiest distros to keep tidy. There's people that have been running the same install for many years. On the other hand, whenever I try dist-upgrade in Debian et al. I always end up blowing up something.
- creshal 11y ago
  Debian can be configured to be quite tidy, and apt less suicidal, but it requires far more effort than on Arch. However, once set up, you can slap unattended-upgrades on top and have a (usually…) self-updating and self-maintaining system, which is quite neat.
  - nextos 11y ago
    Oh yes. Well, Debian is very nice too, but they have completely antagonic philosophies. Probably the way to go is Nix/Guix. Transactional upgrades and declarative configuration.
  - skrause 11y ago
    On Debian-based systems you can simply use debfoster (https://packages.debian.org/debfoster https://packages.debian.org/debfoster) to remove unwanted packages.
    - shared4you 11y ago
      What does this do that `apt-get autoremove` doesn't?
      - onli 11y ago
        I remember this having existed before autoremove. It shouldn't help much now.
      - skrause 11y ago
        apt-get autoremove only removes now unused packages that were previously installed automatically as a dependency. debfoster explicitly asks you which packages you want to keep and removes everything else. You can use it to strip down an existing Debian installation to just the base packages.
dr4g0n 11y ago
I was really thrown by the ligatures in some of the command snippets (diﬀ and lostﬁles). Why do things manually have to be marked as dependencies? Is that because they were manually installed at one point, or does Arch's package manager not properly track dependencies?
- rakoo 11y ago
  If a package really is installed as a dependency, it will be marked as such. If for some reason you manually install a package that is needed by another one, then it's a good thing to mark it as dependency. In the case of cleaning your system, it is interesting to mark an unused package as a dependency; the resolver (see https://www.archlinux.org/pacman/pacman.8.html#_remove_options_a_id_ro_a https://www.archlinux.org/pacman/pacman.8.html#_remove_optio...) will see that it's installed as a dependency, but no package depends on it. It's a quick way to "tag" them as unused so they can be "garbage collected" at a later time.
nly 11y ago
Here's a handy one. It lists packages that are both explicitly installed (and therefore won't be removed unless you remove them yourself), but are also needed by other packages. comm -23 <(pacman -Qqe | sort -u) <(pacman -Qqet | sort -u) And here's a more practical version that ignores the base and base-devel group (I don't know why package maintainers keep adding things in base like glibc as direct dependencies, but they do) comm -23 <(comm -23 <(pacman -Qqe | sort -u) <(pacman -Qqet | sort -u)) <(pacman -Qqg base-devel base | sort -u) Unless you have a personal reason to explicitly keep these packages, they usually need to be marked as dependencies again so that, when you remove the things that depend on them with -Rs, they'll be removed as well. pacman -D --asdep packagename If you want to know what depends on each of these packages run pactree -r packagename Sorting this out should eliminate the need to ever resort to a -Rc (--cascade) removal, which is dangerous.
- ackalker 11y ago
  Those are some very useful oneliners, thanks! :) Please consider adding them to the Arch Wiki (if they're not already on it).
erikb 11y ago
A little on the side: Is it possible nowadays to install an Archlinux that out of the box can do about as much as a fresh installed Ubuntu (Gnome, Firefox, a Terminal, Git, mostly)? I've always wanted to try it. But since I'm working full time I don't get around to start an installation with manual FS setup and networking, both topics which I mostly know a few little basics about. Altogether Arch looks much nicer, and I agree that you should have as much control of your system as possible. But I think the approach should be that you can choose to learn only little chunks here and there until you have most of the ideas in your head and fingers, then setup everything as you desire. That's why I'm still stuck on Ubuntu.
- nextos 11y ago
  I think it took me less than 2 hours to do a full install reading the wiki 5 years ago. Now, with systemd doing mostly everything it's a lot simpler. I think it can be scripted in 10 lines of code. I use Arch because I'm quite lazy and I find it straightforward. It doesn't hide anything and there's little magic. It's all about getting your components well chosen. Arch might work well with Gnome, but I think it really shines using a minimal setup with no desktop environment.
  - erikb 11y ago
    I bet you can script it. But for that first you need to know enough about it. That's where the trouble comes in getting started. E.g., a colleague suggested me to put "noatime" into my fstab. Now you might say that's about 5 seconds. But if you don't know what it is and you take responsibility for your system, then what you first do is read about it. So I spent about 10 hours reading and discussing about noatime and then decided not to put it into my fstab because I learned that the default is already "relatime" which is a little slower but much more compatible with some tools. Instead of 10 seconds I've spent 10 hours and in the end didn't change my config at all. That's what I would expect when I get started scripting the setup myself. If I don't do it then using a sensible, community decided default would be better than doing something without investigating. Would you agree?
    - 11y ago
deleted 11y ago
[deleted]
andmarios 11y ago
In Gentoo it would be: emacs /var/lib/portage/world This file contains a list of all packages you emerged manually. Just remove anything that you don't want. Then simply: emerge -uNDa world && emerge -a --depclean This will first update the system and then remove any package that isn't listed or is a dependency of [a package listed] in the world file. Though if you are serious about system maintenance, whenever you emerge a package you don't want in your world file (e.g you may want to re-compile a dependency) you should use the '-1' flag of emerge: emerge -1a dependency I also have my Gentoo 64bit installation since 2007 and have changed 4 or 5 machines since then. There are the occasional problems (as is the case with any distro) but if you are a bit interested in how things work instead of how things get fixed, you can solve them.
zatkin 11y ago
Nice read! Unfortunately, on mobile it's difficult to figure out what the options do individually. Too bad they're not easily predictable. It would be nice if they were written in long form and short form for people like me. I'll have to read through the man page later.

101 points by ilpianista 11y ago

vamur 11y ago

My Archlinux based LiveUSB setup comes around to 1GB and has Libreoffice, Wine, Firefox/Chromium. That said, there are some questionable dependencies in Archlinux lately. For example, mpv now requires smbclient, which then pulls python2.7.

RexRollman 11y ago
There's always been little things like that. For example, installing Feh pulls in libid3tag (which for whatever reason is a dependency of imlib2).
- leni536 11y ago
  Maybe for opening album art? Feh complains if I want to open an mp3 with embedded album art though: feh WARNING: 01.mp3 - No Imlib2 loader for that file format And imlib2 does depend on libid3tag.
  - RexRollman 11y ago
    I know but it's a weird dependency to me. One would think that an ID3 editor would need that, not the image processing utililty itself.
plg 11y ago
Is freeBSD better on this front?
- andrers 11y ago
  Not really. I thought of installing gcc 5.1 through its binary package and it tried to install gcc-ecj 4.5 along with it. I ended up installing it through the ports system, disabling Java support. Its ports are where FreeBSD really shines. They're something in between Arch's ABS and Gentoo's portage. I just wish there was someway to say "install binutils via pkg, and only compile gcc itself".
  - floatboth 11y ago
    pkg install binutils && make -C/usr/ports/lang/gcc install clean :-) You can also `make package` to, well, make your own binary package (it will be in /usr/ports/lang/gcc/work/pkg) to distribute to other machines. Or use poudriere to setup a proper package build server.
creshal 11y ago
The dependencies are mainly insane upstream defaults, which Arch doesn't try to hide. For many packages there are modified PKGBUILDs available in the AUR for these situations (mplayer-nosmb, pidgin-mini, …). Sadly not for mpv (yet, I've been meaning for a while to make one, but didn't yet get around to it).

nextos 11y ago

I've always found Arch to be among the easiest distros to keep tidy. There's people that have been running the same install for many years. On the other hand, whenever I try dist-upgrade in Debian et al. I always end up blowing up something.

creshal 11y ago
Debian can be configured to be quite tidy, and apt less suicidal, but it requires far more effort than on Arch. However, once set up, you can slap unattended-upgrades on top and have a (usually…) self-updating and self-maintaining system, which is quite neat.
- nextos 11y ago
  Oh yes. Well, Debian is very nice too, but they have completely antagonic philosophies. Probably the way to go is Nix/Guix. Transactional upgrades and declarative configuration.
- skrause 11y ago
  On Debian-based systems you can simply use debfoster (https://packages.debian.org/debfoster https://packages.debian.org/debfoster) to remove unwanted packages.
  - shared4you 11y ago
    What does this do that `apt-get autoremove` doesn't?
    - onli 11y ago
      I remember this having existed before autoremove. It shouldn't help much now.
    - skrause 11y ago
      apt-get autoremove only removes now unused packages that were previously installed automatically as a dependency. debfoster explicitly asks you which packages you want to keep and removes everything else. You can use it to strip down an existing Debian installation to just the base packages.

dr4g0n 11y ago

I was really thrown by the ligatures in some of the command snippets (diﬀ and lostﬁles). Why do things manually have to be marked as dependencies? Is that because they were manually installed at one point, or does Arch's package manager not properly track dependencies?

rakoo 11y ago
If a package really is installed as a dependency, it will be marked as such. If for some reason you manually install a package that is needed by another one, then it's a good thing to mark it as dependency. In the case of cleaning your system, it is interesting to mark an unused package as a dependency; the resolver (see https://www.archlinux.org/pacman/pacman.8.html#_remove_options_a_id_ro_a https://www.archlinux.org/pacman/pacman.8.html#_remove_optio...) will see that it's installed as a dependency, but no package depends on it. It's a quick way to "tag" them as unused so they can be "garbage collected" at a later time.

nly 11y ago

Here's a handy one. It lists packages that are both explicitly installed (and therefore won't be removed unless you remove them yourself), but are also needed by other packages. comm -23 <(pacman -Qqe | sort -u) <(pacman -Qqet | sort -u) And here's a more practical version that ignores the base and base-devel group (I don't know why package maintainers keep adding things in base like glibc as direct dependencies, but they do) comm -23 <(comm -23 <(pacman -Qqe | sort -u) <(pacman -Qqet | sort -u)) <(pacman -Qqg base-devel base | sort -u) Unless you have a personal reason to explicitly keep these packages, they usually need to be marked as dependencies again so that, when you remove the things that depend on them with -Rs, they'll be removed as well. pacman -D --asdep packagename If you want to know what depends on each of these packages run pactree -r packagename Sorting this out should eliminate the need to ever resort to a -Rc (--cascade) removal, which is dangerous.

ackalker 11y ago
Those are some very useful oneliners, thanks! :) Please consider adding them to the Arch Wiki (if they're not already on it).

erikb 11y ago

A little on the side: Is it possible nowadays to install an Archlinux that out of the box can do about as much as a fresh installed Ubuntu (Gnome, Firefox, a Terminal, Git, mostly)? I've always wanted to try it. But since I'm working full time I don't get around to start an installation with manual FS setup and networking, both topics which I mostly know a few little basics about. Altogether Arch looks much nicer, and I agree that you should have as much control of your system as possible. But I think the approach should be that you can choose to learn only little chunks here and there until you have most of the ideas in your head and fingers, then setup everything as you desire. That's why I'm still stuck on Ubuntu.

nextos 11y ago
I think it took me less than 2 hours to do a full install reading the wiki 5 years ago. Now, with systemd doing mostly everything it's a lot simpler. I think it can be scripted in 10 lines of code. I use Arch because I'm quite lazy and I find it straightforward. It doesn't hide anything and there's little magic. It's all about getting your components well chosen. Arch might work well with Gnome, but I think it really shines using a minimal setup with no desktop environment.
- erikb 11y ago
  I bet you can script it. But for that first you need to know enough about it. That's where the trouble comes in getting started. E.g., a colleague suggested me to put "noatime" into my fstab. Now you might say that's about 5 seconds. But if you don't know what it is and you take responsibility for your system, then what you first do is read about it. So I spent about 10 hours reading and discussing about noatime and then decided not to put it into my fstab because I learned that the default is already "relatime" which is a little slower but much more compatible with some tools. Instead of 10 seconds I've spent 10 hours and in the end didn't change my config at all. That's what I would expect when I get started scripting the setup myself. If I don't do it then using a sensible, community decided default would be better than doing something without investigating. Would you agree?
  - 11y ago

deleted 11y ago

[deleted]

andmarios 11y ago

In Gentoo it would be: emacs /var/lib/portage/world This file contains a list of all packages you emerged manually. Just remove anything that you don't want. Then simply: emerge -uNDa world && emerge -a --depclean This will first update the system and then remove any package that isn't listed or is a dependency of [a package listed] in the world file. Though if you are serious about system maintenance, whenever you emerge a package you don't want in your world file (e.g you may want to re-compile a dependency) you should use the '-1' flag of emerge: emerge -1a dependency I also have my Gentoo 64bit installation since 2007 and have changed 4 or 5 machines since then. There are the occasional problems (as is the case with any distro) but if you are a bit interested in how things work instead of how things get fixed, you can solve them.

zatkin 11y ago

Nice read! Unfortunately, on mobile it's difficult to figure out what the options do individually. Too bad they're not easily predictable. It would be nice if they were written in long form and short form for people like me. I'll have to read through the man page later.