small Gentoo

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

Hi,

I'd like to build a small Gentoo live ISO with just X and 1 or 2 X applications. I'm hoping to get an ISO <100MB.

I noticed that the embedded stage3 files are quite old:
http://distfiles.gentoo.org/experimental/x86/embedded/
Are they unsupported?

Would I benefit size-wise using musl or uclibc instead o glibc? The stage3 file sizes aren't that different between these:
http://distfiles.gentoo.org/experimental/x86/musl/
http://distfiles.gentoo.org/experimental/x86/uclibc/
and this:
http://distfiles.gentoo.org/releases/x86/current-stage3/

In any case, I started installing from the uclibc stage3: http://distfiles.gentoo.org/experimental/x86/uclibc/stage3-i686-uclibc-hardened-20140305.tar.bz2
but when I chroot into it and emerge, say, mesa, I get compilation errors (that I didn't have when using a glibc stage3).
Should I report the ebuild problems to bugs.gentoo.org even if the stage3 files are "experimental"?

Does anyone know of a clear guide to get X (just the X server and xterm app) on Gentoo with as little software as possible (+- 80 MB)?

I just found Rat Gentoo and will give it a try but was wondering if there was an "official" guide (or an official stage from which to start).

Thanks,

Vieri

xaviermiller · Posted: Wed Mar 26, 2014 2:08 pm Post subject:

Hello,

Take a look at SystemRescueCD (based on Gentoo): the iso is really small but contains A LOT of useful applications.
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Vieri · l33t Joined: 18 Dec 2005 Posts: 877

Hi Xavier,

I actually did take a look at system rescue cd. I even customized it and created an iso. I tried to trim it down to just X and I couldn't get below 400MB, even after removing manually certain dirs (such as devtools, portage, docs, man pages, etc).

It's amazing how slitaz (with X) can be under 40MB, ten times less. I'm hoping to do the same with Gentoo.

khayyam · Posted: Wed Mar 26, 2014 8:34 pm Post subject:

Vieri ...

I think you probably want experimental/{arch}/uclibc these stages seem to be more recent (the last being 20140305) and they are about 114/116MB for vanilla/hardened (x86) respectively. Blueness has been doing quite a lot of work with hardened uclibc (see lilblue) and many of the issue with hardened/uclibc and xorg have been ironed out. You should be able to generate something closer to your desired size by stripping out unneeded docs, manpages, infopages (FEATURES="nodoc noman noinfo") and with the use of package.use, profile/package.provided and (perhaps) INSTALL_MASK. I guess it really comes down to what exactly you need (XFCE for instance will obviously take more space than x11-wm/ratpoison or x11-wm/i3). Lilblue is XFCE based with quite a few GUI tools and its exactly 1GB.

As for compilation, uclibc support is a work in progress, I had one or two issue some time (maybe 8 months) back but they tend to get fixed fairly quickly (again, thanks in part to blueness, aka, "Anthony Basile"). I haven't used xorg with any of these slim targets so I have no knowledge of what the current status is with mesa, but with the above stages you can report it on b.g.o and assign it to blueness (I'm pretty sure he'd want the feedback, but I can't seem to find the blog post where he actually said this ... check is blog ... maybe you'll find it.)

Re musl ... support is still behind that of uclibc, I have built a (non gentoo) system with it using Aboriginal Linux. I don't recommend it unless you have *a lot* of time to troubleshoot.

HTH & best ... khay

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

Thanks khay for the info.
The fact that the uclibc stage3 tarballs start out at 114MB and I still need to emerge X and dependencies means that I'm going to have a very hard time keeping the whole system beneath 100MB even if I remove man and info pages.
Anyway, I'll give it a shot.

Thanks

eccerr0r · Posted: Thu Mar 27, 2014 7:02 am Post subject:

The portage system of Gentoo is probably one big piece that puts a lower bound on how small the install can be. If you omit this, meaning using ROOT= to build a system ala stage1 and leave out portage/emerge/etc., you might be able to get away with a smaller system.

However things have been getting mighty bloaty and even without portage installed, it will still be fairly large. I remember doing this exercise to fit a small X11 capable boot CF card in less than 512MB uncompressed with Firefox installed with space to spare. It's possible but getting more and more difficult as time goes on, due to tons of dependencies that get pulled in... It's mostly trying to keep perl and python from installing somehow... and of course gnome...
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khayyam · Posted: Thu Mar 27, 2014 7:46 am Post subject:

xaviermiller · Posted: Thu Mar 27, 2014 7:54 am Post subject:

Hi Vieri,

Is it 400 MB with squashed rootfs or uncompressed size?
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Kind regards,
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defer- · Posted: Thu Mar 27, 2014 8:47 am Post subject:

Here are some tips for freeing up disk space.

Remove doc, man and info pages
Add to /etc/portage/make.conf
FEATURES="nodoc noman noinfo"
$ rm -r /usr/share/man /usr/share/doc /usr/share/info

Optimize for size
Add to /etc/portage/make.conf
CFLAGS="-march=native -Os -pipe"
CXXFLAGS="${CFLAGS}"

Tweak use flags
Add to /etc/portage/make.conf
USE="minimal -fortran -deprecated -iptables -ipv6"

Strip base system
Remove all unneeded packages from /usr/portage/profiles/base/packages

Use ramdisk
Add to /etc/fstab
none /tmp tmpfs size=128M,noatime 0 0
none /var/tmp tmpfs size=2048M,noatime 0 0
none /var/log tmpfs size=8M,noatime,noexec,nosuid 0 0

Clean up ~/.cache/
$ rm -r ~/.cache/

Rebuild system
$ emerge --sync
$ emerge -eav @world
$ emerge -av --depclean

Use ncdu to find out what takes up disk space
$ emerge -av ncdu
$ ncdu /
If you want to find out which package file belongs. Use equery belongs filename

Remove old kernels and kernel modules
Clean old kernels from /usr/src. You can even remove all kernel sources after you have installed kernel.
Remove old kernel modules from /lib64/modules/

Remove distfiles
Remove all unneeded:
$ eclean -d distfiles
Or remove all:
$ rm -r /usr/portage/distfiles/*
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Vieri · l33t Joined: 18 Dec 2005 Posts: 877

Xavier, that's squashed.

Defer, thanks for the tips.

I'm currently taking a look at https://forums.gentoo.org/viewtopic-t-705771-start-0.html which uses glibc and I may not have as many compilation problems as with uclibc.

khayyam · Posted: Thu Mar 27, 2014 10:13 am Post subject:

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

I noticed that what's really killing my intent of keeping the system small is trying to install CUPS. I really need to install a "printer server" so users can print directly with a URI (ipp://, http://host:631/printers/name).
Any ideas of how I can reduce the size of the CUPS installation (and dependencies)?
Or are there alternatives to cups, like dropbear is to openssh?

cwr · Veteran Joined: 17 Dec 2005 Posts: 1969

If I wanted something really small I think I'd start with Puppy or DSL or TinyCore.
At least checking them would give you an idea of what packages are needed,
whether you used the actual distro or not.

Will

eccerr0r · Posted: Fri Mar 28, 2014 1:48 pm Post subject:

Hmm. CUPS wants to install ghostscript, which is a "huge" package...
Do you need to translate file formats is the question, and if you do, ghostscript is needed.

Else you could install lprng or something that doesn't know how to convert file formats?
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Vieri · l33t Joined: 18 Dec 2005 Posts: 877

eccerr0r, I believe lprng doesn't support IPP/HTTP printing.

By the way, when installing packages with ROOT=TARGETDIR emerge PACKAGE, won't ebuild commands such as enewgroup fail? For instance, if I do ROOT=/target emerge cups then a new user and group are create in /etc/passwd and /etc/group but NOT in /target/etc/{passwd,group}.
That's because /usr/portage/eclass/user.eclass uses commands such as getent and groupadd which I believe know nothing about the ROOT/target dir.
I would have to chroot into my target dir and create the group myself but I was wondering if there's a fix or a better workaround for this.

eccerr0r · Posted: Tue Apr 01, 2014 1:28 pm Post subject:

You're probably stuck with cups then, and have to take ghostscript along.
Hmm... I wonder if sandbox should be used to detect this situation and they should be flagged as a bug. Honestly I gave up on the ROOT= method, I tend to make all my Gentoo installs self-updating and use another, binary Linux distribution if disk space is that much of a concern. Updates are very important for security, and a Gentoo without portage is kind of a lame install...
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cwr · Veteran Joined: 17 Dec 2005 Posts: 1969

I _thought_ that CUPS without the doc flag avoided Ghostscript, but the world may have
changed while I wasn't looking. Generally in limited space you want "-doc" in make.conf
anyway.

Will

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

I managed to create a 61MB iso file that I could load with PXE. [EDIT: rebuilt with -Os and -fomit-frame-pointer as well as removed some more unneeded subdirs and got 55MB iso of which 32MB as squashfs and the rest as kernel image and initramfs]
Besides a few console utilities it has X, rdesktop and a custom fltk app.
The interesting thing is that it's NOT based on busybox and uclibc.
I made it from a "release" stage3 (i486) with glibc.
I'm 14MB away from a slitaz-cooking iso but I'm quite happy with what I could do with Gentoo.

I also created another target with all of the above plus cups/ghostscript, extra ppds, ccid, pcsc-lite. That came up to around 115MB (the iso).

I'm wondering if size reduction would be significant if I were to use uclibc or if it's not worth struggling with the compilation issues.

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

Just for the record, the minimal system with X, rdesktop, etc., packaged as a 55MB glibc ISO (-Os -fomit-frame-pointer) as mentioned in my previous post was rebuilt with the experimental uclibc stage3 and the ISO file size was brought down to 47MB. Correct me if I'm wrong but I don't see any significant size advantages between uclibc and glibc when using certain optimization flags.

khayyam · Posted: Tue Apr 08, 2014 9:23 am Post subject:

beandog · Posted: Wed Apr 09, 2014 6:28 am Post subject:

beandog · Posted: Wed Apr 09, 2014 6:35 am Post subject:

Okay, so it's late at night, and I'm stuck at work, so this may be a bit rambly ... but .. how are you guys installing TO your target OS anyway?

Here's how I've done it in the past ... I use buildpkg in FEATURES and then with the new install, I do emerge -KO package with a HUGE install mask that strips out all development files, unnecessary nls files, etc, etc, etc.

I was pretty hardcore about removing as much as possible. There's a lot of binaries you don't need ... busybox is nice, but sometimes you need the extra functionality.

I notice there's a tendency to worry about the number of dependencies, but these libraries come in really small files in the long run, for the most part.

Also, this may answer someone's earlier question, but look at emerge --config-root to pull in a separate portage/make.conf enviroment.
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Vieri · l33t Joined: 18 Dec 2005 Posts: 877

The feedback on this thread as well as other blogs on the web helped a lot and I'm happy to see that I could build a very small target system with my favorite distro (Gentoo). I didn't manage to get it as small (and feature-packed) as eg., Slitaz but I'm getting close enough. I'm sure I can further tweak the target and slim it down some more.

Thanks all

Vieri · l33t Joined: 18 Dec 2005 Posts: 877

I'm having some minor issues understanding emerge/portage.

Within my "build environment" with 'buildpkg' FEATURE in make.conf I ran: