Linux Section

GoboLinux : breath of fresh air?

My very first reaction to GoboLinux was negative. The underlying idea of taming the Unix/Linux file system hierarchy with symbolic links isn't new: heck, SCO did that way back with their 3.2v4.0 release, and for exactly the same reasons (see the Software Storage Objects- SSO section at this link). Most of us in the field agreed that the concept was laudable in theory but failed in practice: too many places where it broke down. See Speaking of symbolic links... for some taste of that. The basic flaw of this sort of scheme is that symlinks are easily broken; there's no warning that removing /Foo is going to remove access to the entire hierarchy that appeared under it. Oh, of course the things /Foo pointed to aren't gone, but that doesn't make things less broken when it happens.

But.. you know, the more I read about GoboLinux (especially the "I am not clueless" article), the less certain I became that this is a foolish Don Quixote effort. Yes, yes: ``Those who do not understand Unix are doomed to reinvent it, poorly.'' - Henry Spencer, 1987. Yes, yes, it's not hard to find examples of GoboLinux having broken link problems. Nor is it hard to find people vehement in their opposition. But the split between those who like it and those that do not might be pretty even: this poll at the Ubuntu Forums showed 42.59% liking the concept and only 35.8% opposed (21.6% were neutral). That was only 162 people, but it shows that this isn't "obviously" bad.

The file system links aren't the only oddities: neither BSD or SysV style rc scripts are used. Instead /etc/inittab has "/System/Links/Executables/BootDriver" - a shell script that replaces all that. There's also no "root" name in /etc/passwd: the id 0 user is "gobo". I'm still not clear on why that was done, but of course it's easy enough to change (and the docs even speak of perhaps allowing the installer to choose id 0's name).

I was also thinking that the inherent weakness of too easily removed links could be at least partially solved with acl's and extended attributes. Of course that would also make upgrades more cumbersome, but that's unavoidable: symlinks always cause problems for somebody. You can move the problem around, but it is always somewhere waiting to bite. That doesn't necessarily mean that GoboLinux is a bad idea: symbolic links can solve a lot of problems too.

If you aren't groaning and wondering how on earth I could be so stupid as to not see what an epically horrible idea all this is, you might want to poke through the GoboLinux Knowledge Base. If you are shaking your head and feeling sorry that I've lost all my marbles, trust me: I understand how you feel and why you feel that way. I'm not so enamored of this idea that I'm evangelizing it, but neither am I as against it as I thought I would be. I probably fall into some grey area between completely neutral and liking it, while at the same time reserving quantum rights to be mildly opposed at the same time. I guess I'm still highly ambivalent about GoboLinux..

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Tue Dec 19 15:23:29 2006:   BigDumbDinosaur


I personally never had any issue with the extensive use of symbolic links in SCO OSR5. It is a dumb administrator, in my opinion, who deletes things without knowing why they are there. Assuming that said admin understands that /etc/tcp is actually a symlink to /var/opt/K/SCO/tcp/2.1.1Ga/etc/tcp and that removing the link would break his system, he would not disturb it.

SCO's extensive use of symlinks makes sense when you consider the modularity of the system. Functionality can be readily added or subtracted without making major shifts to the filesystem. If a newer version of, say, the tcp subsystem is installed, switching to it is as simple as redirecting the appropriate symlinks.

One aspect of a heavily symlinked filesystem that may be overlooked is that each access to a symlinked file requires two directory searches: one for the symlink entry and another to get to the actual file. Although it is essentially inperceptible on modern hardware, this does add some to execution time.



Tue Dec 19 15:30:26 2006:   TonyLawrence


The problem isn't dumb administrators, it's dumb programs that act in unexpected ways when presented with symlinks..





Wed Dec 20 00:53:21 2006:   drag


hehe.
Just be happy that we don't have context-dependant symbolic links for Linux.

Could you imagine all the bizzare things people would do with that?

I ran into a file system taht supported them when messing around with OpenSSI (single system image). It combined multiple computers into one. It used symbolic links based on node number to redirect node-specific files and directories.


Do you want to see a heresy even worse then mucking around with the unix directory layout?
A Linux registry!!
http://elektra.g4ii.com/Main_Page

It's very interesting. Instead of some binary database it would use regular file system layout. With directories instead of text files and then XML text files that replace sections out of the configuration file. Each text file contains a single keyword and corrisponding value.

So there would be a xorg.conf directory, with 'monitor' directories and 'layout' directories. Then inside those directories would be a text file that contain the actual information.

So it's easy to backup, easy to edit by hand, easy to program for. They provide system libraries and utilities that are small enough you can pack them into a initrd file without any effort, and other programs can call on those libraries to deal with configuration issues.

They even maintain some patched versions of common Linux stuff like X.org that uses their configurations.

(To bad for them X.org is eliminating the traditional X configuration file. They are going to move to a dbus, hal setup were configurations are done on the fly, mostly.)

That way if everybody uses it you keep most of the advantages of text files, but gain the ability to write very simple, but very effective configuration utilities for admins and desktops to use.



Tue Aug 28 14:54:17 2007:   anonymous


"Do you want to see a heresy even worse then mucking around with the unix directory layout?
A Linux registry!!"

Thats not so much a heresy.
A registry per se isnt that bad, but people always associate it with Windows.

If a registry makes life easier, it might find its way.

The problem though is that its based on XML and XML really tends to just grow in complexity over time, and when it grows, it ultimately starts to suck. I have noticed this happen over years over and over again. I think XML simply is not suited for humans, its only suited for parsers...

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