Finnix development update

About two weeks ago, I had surgery for a somewhat serious injury. The weeks leading up to and since the surgery have given me a lot of time to work on personal projects (for the weeks before the surgery I was on strong painkillers which messed up my sleep, often keeping me up in the middle of the night, and the weeks since have been in recovery), which let me get Finnix 106 out the door earlier this week.

It has also given me time to make some long-desired architectural changes to the development environment, beginning with Project NEALE during the Finnix 105 development cycle. Here is a short update of what's changed lately.

As part of Project NEALE, all components of Finnix not contained in the compressed root (the CD layout, initrd, kernel and miscellaneous files) are now stored in udeb packages (neale-master, neale-initrd, neale-kernel and neale-stuff, respectively), which are extracted as part of build-neale. The method is slightly unusual; for example, the neale-kernel and neale-initrd source packages contain sources, as well as pre-built binaries for all supported architectures. But the net effect is all non-Debian sources are now contained in packages at archive.finnix.org. If you need the sources for a Finnix kernel from 106 onwards, grab the source package for neal-kernel.

Through Project NEALE, Finnix now has support for building ISOs with AMD64 userlands. While Finnix will not be releasing an official ISO with an AMD64 userland (for reasons explained on the Project NEALE wiki page), it is a testament to the versatility and abstraction that NEALE allows versus the old, manual method of assembling releases.

Packaging for all Finnix packages are now being managed in version control via bzr on Launchpad. I sent a mail to the debian-derivatives list recently, detailing my experiences in undertaking this.

The archive at archive.finnix.org is managed by a tool called reprepro, a mid-end system for managing Debian-style apt repositories. I have written a plugin for reprepro, which takes source uploads, scans for changelog entries with "LP: #12345" (the same format Ubuntu uses), and will update the corresponding bug's status, add an "archive-fixed" tag, and add a comment with a copy of the .changes file. This is similar to what both Debian and Ubuntu do on their respective bug tracking systems.

And example of a recent Finnix bug fixed by a source upload is here. Originally the plugin was specific to Finnix, but I have expanded it to be a general purpose tool. So if you manage an apt repository with reprepro and also use Launchpad for bug tracking, this tool may be of use to you.

Finnix development on Launchpad

I am experimenting with tracking development on Launchpad, specifically bug tracking and new features. A number of bugs have already been filed for the Finnix 104 milestone. If you have a bug or a feature request not already listed, please file a bug through the Launchpad interface.

The mailing list will continue to be the focal point of Finnix discussions, and Launchpad will not be used for things like package management. Still, it's already proving to be a decent bug tracking interface, and beats the method used for the previous 12 years (namely, a text file in a screen session on a development machine).

New compression for Finnix 102

In my previous post, I mentioned switching to xz compression without much explanation.

Software tends to get larger over time. Finnix deals with this in two ways: looking for things to cut while still retaining as much functionality as possible, and just accepting that the size will continue to grow over time. Larger kernels, larger software, etc. The smallest release of Finnix was Finnix 86.2, at 92 MiB (x86). The last release, Finnix 101, was the largest so far at 128 MiB (x86).

During development of Finnix 102, the simple act of adding upgraded kernels and upgrading existing Debian packages to the latest versions was seriously adding to the size of Finnix, nearly 150 MiB at one point. And I had done all I could to reduce the size; there was just nothing left to cut out. Then I found out about xz compression. Xz is based on LZMA2, offers 10-20% more compression than Gzip, and in particular has optimizations for architecture-specific bytecode (program binaries, etc). Xz support was added to Linux 2.6.39, and could be used for kernel, initrd and SquashFS compression (previously, all three used Gzip compression).

So I tried it out, using Linux 3.0-rc (as of right now, if 3.0 comes out soon, it will be included with Finnix 102). I used xz compression for the kernel, initrd and SquashFS root filesystem, and was seeing 20% space savings versus using Gzip.

No compression:
  Root FS:    385,187,840
  initrd:       7,534,080
  Final ISO:  400,162,816

Gzip compression:
  Root FS:    136,921,088 (64.45%)
  initrd:       2,495,967 (66.87%)
  Final ISO:  146,857,984 (63.30%)

Xz (LZMA2) compression:
  Root FS:    109,469,696 (71.58% none, 20.05% gzip)
  initrd:       1,733,032 (77.00% none, 30.57% gzip)
  Final ISO:  118,644,736 (70.35% none, 19.21% gzip)

Overall, it looks great. Though one consideration is performance. LZMA is known for being very processor intensive. LZMA2 is more processor efficient than LZMA (and BZ2), but still slower than Gzip. Compression times are roughly 5 times slower than with Gzip. But the real question is how well decompression would work in the real world (that is, when booting Finnix). I don't have any hard numbers on that, but I did put dev builds through the gauntlet of everything from an i586 AMD K6 to a Power Mac G3 to a Core 2 Quad Q9450, and could not perceive any slowdowns.

So barring any major problems, Finnix 102 will actually be smaller than its predecessor, for the first time in over 3 years.

As a reminder, the standing goal of Finnix is to keep the distribution CD below the size of a Mini CD (185 MiB). While I doubt many people actually use Mini CDs, it's a good round goal, and while Finnix would still be within the 185 MiB limit without xz compression today, a proactive approach to keeping the distribution size low helps it from becoming a crisis too quickly.

By the way, the build scripts have been updated to allow a builder to choose which method of compression (xz, Gzip, or even none), and scripts within Finnix that rely on reading/modifying the initrd (finnix-netboot-server, for example) have been updated to detect which compression method is being used, and will use that method when rebuilding the initrd.

Finnix 102 development status

Finnix 102 is coming along well. At this point, everything on my list is done, and I'm just waiting for Linux 3.0 to be finalized (I've been testing against 3.0-rc builds for awhile, with good success). A changelog so far (subject to change before final release):

* dist-upgrade
* Upgraded kernels to 3.0 (Debian 3.0.0-xxx)
* Added xen-blkfront to the initrd (AMD64 kernel)
* Added initrd loading attempt of xen-blkfront and xen-netfront
* Added ability to set manual IPv4 addresses and basic resolv.conf info via boot parameters
* Changed kernel, SquashFS compressed root, and initrd to xz compression
* Changed finnix-netboot-server and finnix-netboot-biginit to detect gzip/xz/uncompressed initrd, and build initrd_net accordingly
* Fixed console boot flag
* Fixed automatic update of /etc/fstab during hotplug device update
* Upgraded Memtest86+ to 4.20

The current x86 dev build is 2520, which gave me the idea to go back and look at what builds corresponded to what releases.

* 86.1: 1435
* 86.2: 1504 (+69)
* 87.0: 1617 (+113)
* 88.0: 1776 (+159)
* 89.0: 1961 (+185)
* 89.1: 1969 (+8)
* 89.2: 2011 (+42)
* 90.0: 2084 (+73)
* 91.0: 2154 (+70)
* 91.1: 2185 (+31)
* 92.0: 2270 (+85)
* 92.1: 2296 (+26)
* 93.0: 2318 (+22)
* 100: 2359 (+41)
* 101: 2473 (+114)

Prior to the 86.0 release, I picked build #500 as a rough guess as to how many builds I had made since then. 86.0 itself didn't have the build number shown publicly, so I don't have that data. Most testing is done on a VM (formerly VMware, today VirtualBox), so comparatively few builds are actually burned to CD (I would estimate about 200, which is still a lot). But nearly every build has at least been booted.

PowerPC builds use a different build number which is much smaller, 226 as of today. This is because the primary dev machine is an older G4 Mac Mini, which takes much longer to build compressed roots (formerly about 5 minutes, now over 20 minutes due to the switch to xz compression as mentioned in the changelog), compared to a minute or so on x86, a Core 2 Duo E7200. So most development and architecture-agnostic testing is done on x86 in a VM, then the changes are transferred over in bulk to the PPC environment and built.

Finnix remastering updates

Finnix is used a lot for remastering for administrators' specific projects, so if you're a remasterer, you're going to both love and hate Finnix 101 -- love because Finnix 101 ultimately makes it a lot easier to remaster in the long run, and hate because a lot of things have changed in incompatible ways, hopefully for the better. This post should help give you a rundown on what's changed.

The following wiki guides have been updated for Finnix 101:

CD layout

  • Almost everything with the CD layout has changed. All filenames are now lowercase, and most files have changed locations.
  • md5sums is now on the root of the CD (/md5sums).
  • /isolinux and /boot are still the bootloader-specific directories for x86 and PowerPC, respectively.
  • /{isolinux,boot}/minirt has become /{isolinux,boot}/initrd.gz.
  • /FINNIX/FINNIX has become /finnix/arch/{x86,ppc}/root.img, where "x86" and "ppc" are the userland identifiers for the architecture (that is, you don't have to worry about 64-bit kernels on the 32-bit userland).
  • /finnix/arch.map is a text file that defines a `uname -m` mapping to the userland architecture. The first column is the output of `uname -m`, the second is the primary userland architecture, and the third is the secondary userland architecture. On 64-bit kernels ("amd64" and "ppc64"), the primary userland architecture is "amd64" and "ppc64" respectively, but since Finnix does not distribute 64-bit userlands, it will move on to the secondary columns. Once a root.img is found, that userland architecture is remembered, so overlays will not be checked in the userland architectures that are skipped over. (Short summary: don't use /finnix/arch/{amd64,ppc64}/, it's basically disabled in its current state.)

Build enviroment

  • The default (and recommended) build environment path has changed from /mnt/hda1/knx/ to /finnix/build/. All subdirectories remain the same (source/FINNIX/ for the chroot, initrd/ for the initrd, master/ for the CD layout).
  • The build scripts are now located in the compressed root, and are guaranteed to be the scripts that built the running Finnix version. They are finnix-build-stage1 and finnix-build-stage2. Stage 1 preps the chroot and builds the root.img file, while State 2 builds the initrd and masters the CD. While the build scripts live inside the chroot, they MUST be run from outside the chroot. That is, /finnix/build/source/FINNIX/usr/sbin/finnix-build-stage1 && /finnix/build/source/FINNIX/usr/sbin/finnix-build-stage2.

In the chroot

  • When chrooting in, you should really be doing: export FINNIXDEV=1; chroot /finnix/build/source/FINNIX /bin/bash -l. Setting FINNIXDEV=1 sets some bashrc functionality that makes it easier to work in the chroot, and will temporarily move dummy invoke-rc.d and start-stop-daemon scripts into place so installing/upgrading software within the chroot doesn't try to start daemons, and will automatically mount /proc and /sys when useful.
  • The startup system is now in /etc/finnix/rc*.d/. /etc/rc*.d/ will not be checked at all during Finnix bootup. If you want to start daemons on startup, shell scripts in /etc/finnix/rc2.d/ are the way to go. Additionally, much of the old finnix-autconfig functionality (the mega script that did almost all the heavy lifting) has been split up into components in /etc/finnix/rcS.d/ and /etc/finnix/rc2.d/.

Overlays and local startup scripts

  • On the CD, /FINNIX/overlay.d/ has become /finnix/arch/{x86,ppc,indep}/overlays/. Use x86 and ppc for architecture-specific overlays, and "indep" for architecture-independent overlays.
  • /FINNIX/finnix.sh is gone, in favor of /finnix/arch/{x86,ppc,indep}/rc/. Here you can place multiple local startup scripts. The same architecture rules apply as above.

Finnix 101: What to look forward to

I'll be honest, Finnix 100 was a rush job. Not a bad rush job per se; I have found no major problems with it and continue to use it on a daily basis. But there's nothing particularly great about it. The entire development cycle was about 2 weeks, to get a release out the door to reverse a one-year hiatus. Just enough to bring the software up to date, compile a new kernel, and run through regression testing.

Finnix 101 will be different. I've been working non-stop since October, and behind the scenes, Finnix has basically been completely re-engineered. To a casual eye, nothing will look different. Same boot menus, same minimalist boot, same quick boot times, same overall look. That's fine -- that's what gives Finnix its appeal. But the underlying architectural changes have been a long time coming, and will be useful for development and re-development (that is to say, remastering).

The current dev changelog is quite long by now, but here are a few highlights:

  • As mentioned in a previous post, PowerPC support is coming back!
  • A new kernel, most likely. Debian testing is still on 2.6.32 due to the freeze, but I've been testing 2.6.36 for awhile and it's been stable.
  • The Finnix CD is now 100% self-building. Before you could remaster Finnix from within Finnix, using a set of downloaded scripts (which sadly, I rarely updated). But now the scripts (finnix-build-stage1 and finnix-build-stage2) are located within Finnix itself, and the build scripts on the CD are guaranteed to be the scripts used to build the official release.
  • The CD ISO layout has been completely changed. All files/directory names on the CD are now lowercase, to guard against accidental renaming when on a USB key, for example. Instead of the main compressed root in /FINNIX/FINNIX, it is now in /finnix/arch/$distarch/root.img, where $distarch is amd64, x86, ppc64 or ppc. Since Finnix is only distributed with 32-bit userlands, the locations will be /finnix/arch/x86/root.img and /finnix/arch/ppc/root.img. But if a 64-bit userland were added, amd64 and ppc64 root.img files could simply be added and Finnix would use them if available and usable. /finnix/arch.map contains a list of `uname -m` to $distarch mappings, so adding completely new architectures would even be easier. The map file allows for 64-bit to 32-bit fallback, which allows you to use a 64-bit kernel, and Finnix will look in, say, /finnix/arch/amd64/ first, then /finnix/arch/x86/ as a fallback.
  • With the above in place, it will now possible to make a hybrid x86/PPC CD. With the new layout, the two CDs can essentially be merged into one, and with some mkisofs magic, the combined CD can be made bootable on both arches. I don't plan on releasing a combined ISO, but I do plan on releasing the script to allow you to create one yourself.
  • A Finnix-specific SysV-compatible RC system has been created for booting the distribution. In the past, Finnix essentially fought against Debian's RC system, removing Debian's symlinks in /etc/rc*.d/ and replacing them with Finnix-specific scripts. With Debian's move toward a concurrent boot system, this has become more difficult, so Finnix will simply be using its own separate system in /etc/finnix/rc*.d/ instead. (Indeed, it is a fork of Debian's sysv-rc.)
  • With a Finnix-specific RC system, it is now much easier to break the Finnix sysinit boot into component scripts. All previous versions of Finnix essentially used one giant boot script, so this will allow sysinit-type tasks (such as scanning the PCI bus) to be placed separately in /etc/finnix/rcS.d/, and traditionally userland tasks (such as starting mouse services or an optional SSH daemon) in /etc/finnix/rc2.d/. The userland tasks have been split out and will be ready for Finnix 101, but the sysinit tasks may not be completely componentized for the release.
  • A new netboot helper script has been added, finnix-netboot-biginit. This allows you to create a netboot initrd that contains the entire Finnix distribution within itself. The benefit is you do not need an NFS server to netboot Finnix, only a TFTP server. The downside is you will need more than twice the memory as the size of the distribution, at least 512MB. (There are several stages during boot where the initrd will need to be stored in memory twice; the initrd system was not exactly designed for 1XXMB initrds to be loaded efficiently. Once the boot is completed though, you will only be storing 1x the distribution size in memory, plus standard OS overhead.)
  • The initrd can now automatically detect whether AUFS and/or UnionFS are available. This will help VPS providers deploy Finnix using their kernels, picking whichever module is more convenient for them to implement.
  • On x86, Hardware Detection Tool has been added to the boot menu, which allows you to view system information quickly, without booting into a full operating system.
  • Many smaller improvements and bugfixes are of course included.

The release is feature complete, and I was hoping for a Christmas launch, but at this point I don't think I can go through the required testing and get the ISOs to the mirrors in time. 3 months since Finnix 100 will be late January, though I hope to have a release before then.

Finnix not dead, just resting

Today is the 5 year anniversary of the "modern" incarnation of Finnix, which started with Finnix 86.0. Happy birthday, Finnix!

I sent a message to the Finnix mailing list today, apologizing for hiatus Finnix has been on for the last year, and detailing a roadmap for the near future. Please read the post for the full details, but the main points are:

  • I am now working on Finnix again.
  • Finnix version numbering will jump from 93.0 to 100, and will simply increment with new releases.
  • While Finnix-PPC isn't completely dead, it is no longer a release goal.
  • The Store will be closed, and replaced with a Sticker Exchange.

State of the Finnix

Reposting an email I sent recently:

Yes, I started a few weeks ago after a (too long) hiatus. 2.6.30 kernel, which is looking nice. (SquashFS is now included in mainline. That means UnionFS is now the only kernel patch that is absolutely required.) The latest Debian testing stuff itself is pretty stable, but managed to break pretty much all of Finnix's init scripts in one way or another, but it's coming along. Unfortunately Debian's base packages are a little larger, and the kernels have ballooned between 2.6.26 and 2.6.30, so this will probably be the largest Finnix to date, about 125MiB for x86 at current estimates. It's still well under Finnix's long term goals (never to exceed 185MiB, the size of a mini-CD), but unfortunately there really isn't anything to trim.

Still, I'm happy with what the next release is shaping up to be. Looks good!

Finnix 92.1 soon...

... or the "I waited 5 months for this?" release.

Hopefully a release announcement will be made tomorrow; otherwise it will be next week, as I will be on vacation for the Thanksgiving holiday. Finnix 92.1 will be a maintenance release, with a dist-upgraded environment, a "new" kernel, 2.6.26 (2.6.27 has not yet entered Debian due to the Lenny freeze, and I didn't deem it important enough to break with procedure and use a vanilla kernel this time around), and a few small fixes.

Also, a little teaser: This will not be released with Finnix 92.1 -- it will be sometime after release -- but I will be announcing Finnix on a new architecture. Which one? It's a secret... One hint is it is an architecture I have discussed in relation to Finnix before.

(No, it's not that iPod April Fools port from 2006.)

Finnix 92.0 coming soon

Finnix 92.0 will be released soon. It will have a new 2.6.25 kernel, updated software, and, most visibly, a new boot menu.

There have been suggestions for a new boot menu for awhile now. I liked the idea in theory, but there were various problems with most implementations (no graphics; graphics, but no fallback to text mode; no easy way to add boot options, such as toram, testcd, etc; no way to default to 64-bit boot options). Debian's recent announcement of debian-installer for lenny beta 2 introduced a new installer boot menu system based on bootmenu.c32, which looked very nice and solved most of the problems I mentioned. However, no default 64-bit option on multi-arch CDs, which the announcement mentioned and lamented.

I used Debian's configs as a base for a Finnix test. The results were very nice, and I was ready to do as Debian did and accept that the improvements were worth the loss of 64-bit autodetection. However, an acquaintance encouraged me to look into it ("Sounds like it's time for some OPEN SOURCE MAGIC"), and within a few hours, I had a working patch.

The debian-installer guys loved it and had the patch applied within an hour, and as well, it will be in Finnix 92.0. Here's a development screenshot: