Date: Tue, 24 Apr 2001 02:28:30 -0500 From: Andrew Hesford <ajh3@chmod.ath.cx> To: "Albert D. Cahalan" <acahalan@cs.uml.edu> Cc: matt@fear.net, freebsd-questions@FreeBSD.ORG Subject: Re: How Is The FeeBSD OS Like and Different Than Say Redhat or Suse LINUX Message-ID: <20010424022830.A6085@cec.wustl.edu> In-Reply-To: <200104240533.f3O5Xr304341@saturn.cs.uml.edu>; from acahalan@cs.uml.edu on Tue, Apr 24, 2001 at 01:33:54AM -0400 References: <200104240533.f3O5Xr304341@saturn.cs.uml.edu>
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On Tue, Apr 24, 2001 at 01:33:54AM -0400, Albert D. Cahalan wrote: > > Thomas (Matt) Barton writes: > > > Another great thing about the ports collection is that everything > > gets installed in /usr/local. I don't have to worry about /etc > > getting cluttered, as well as /bin, /usr/sbin, etc. There are a > > few exceptions, of course, such as qmail which goes to /var/qmail, > > but that is about it. > > Every FHS-compliant Linux distribution reserves /usr/local > for _you_ to use. It is for _local_ stuff only. > > Doesn't this make sense? If you compile a home-grown or self-ported > app for FreeBSD, where would you put it? I hope you don't dump it > in /usr/local with all the stuff provided by FreeBSD! It looks like > you need a /usr/local/local or /usr/local_I_REALLY_MEAN_IT for this. > > Putting emacs under /usr/local is a relic from the days when > you'd buy a real UNIX system without emacs. It made sense, > since you were installing local (your site) additions. Now you > get emacs on a CD-ROM along with the rest of your OS. > > Why worry about /etc becoming "cluttered" anyway? You only push > the problem into another location. Now /usr/local/etc is cluttered. > If you simply want to cut the "/bin/ls" output in half, then you > might do better with /1/etc /2/etc /3/etc... but why at all? > If performance is a problem, work on the filesystem. If being hard > to glance over is a problem, you don't gain anything by having > more places for junk to collect. No, the FHS doesn't reserve /usr/local for _you_ to use. It reserves /usr/local for site-specific programs. You illustrate the ass-backwards mentality that linux subscribes to, dumping every package into /usr. So now, forced by foolishness into a lesson of what "site-specific" means, here we go: "Site-specific" means, quite simply, software that is individually selected, and varies from system to system. This naturally includes stuff you build, but it also includes stuff you install from packages. It is important to note that "locally compiled" and "site-specific" are NOT the same thing. This is where linux distributions, like RedHat and Debian, seem to be confused. We know what comprises "locally compiled" software, but what about "site-specific"? To demonstrate this, first look at the complement of "site-specific": "site-inspecific". Site-inspecific software is not software that "feels" like it is fairly standard, and it is not what you and your buddies agree is universal. It is software that is installed in the vast majority of systems of the same type (in this case, FreeBSD). We will call this the "base system", and in order to ensure that it is installed in the vast majority of systems, it must be that this software must be explicitly removed if it is not wanted. The FreeBSD base (all the stuff in /usr/src) satisfies this condition. When you install FreeBSD, all those programs are on your system. If you don't want some of them, you must explicitly remove them by adding entries to /etc/make.conf, and manually removing the files associated with the programs you do not want. This means the FreeBSD base is site-inspecific, which means it is not site-specific (the two are mutually exclusive), so it does not belong in /usr/local. This is why /usr/src programs install in / and /usr. Packages, on the other hand, vary from system to system. Whether they are compiled locally or by somebody else, they are site-specific, since they are not located on the vast majority of systems. For instance, the presence of GNOME or KDE can vary from system to system. I have GNOME because I need it to run gnucash. If I didn't have gnucash, I wouldn't have GNOME. I do not have KDE. Either way, these programs belong in /usr/local, because they are not a part of the site-inspecific system. Neither is gnucash; consequently, it belongs in /usr/local. You will notice that vi is in /usr/bin. This is in the /usr/src tree and is installed on every system unless manually removed. However, its cousin vim may not be present on all systems (and must be explicitly selected), and so vim goes into /usr/local/bin. I do not have emacs, and you can bet a great deal of vim users don't keep emacs around. This is why emacs goes in /usr/local: not because it has historically been put there, but because it is site-specific. Of course, even if you do take the ridiculous position that only self-compiled programs belong in /usr/local, remember that every port is locally compiled. Hence everything except the stuff in /usr/src belongs in /usr/local by your own standard. The prebuilt packages are simply a drop-in replacement for ports; it would be an administration nightmare if locally-compiled ports were intalled in a different location than the packages built from the ports tree. That being said, I can tell you exactly why this poor placement practice has been effected in the linux world. The answer is that linux has no real base system. Pretty much the only thing you can count on between distributions is the kernel, and the GNU file utilities. In fact, this is just about all the Debian distribution leaves you with after install, if you choose not to select packages. The result is that Debian's base is about 20M, consisting of basic file utilities, a kernel, and the necessary tools to install more packages. It would seem foolish to have /usr populated with <20M worth of programs; hence they dump all packages into /usr, and say /usr/local is reserved for self-built programs. No reasonable mind can confuse "site-specific" with "locally-compiled". What we see here is a practice of dumping everything in /usr because linux distributions have no consistent base, and ad hoc explanation for this practice to put people at ease. Over the years this practice has been implemented, people have been brainwashed into thinking this is a logical way of organizing a filesystem, but the truth is, where everything is largely package-based as it is in Debian, the result is virtually all programs are stored in /usr and almost nothing is kept in /usr/local. This is highly disorganized. In this respect, it can be said that FreeBSD follows the Linux Filesystem Standard better than any linux distribution! Before you attack me or try to explain the reasoning behind this lack of organization, do take the time to consider: 1) /usr/local is reserved for site-specific software. 2) Everything in the ports tree (and the packages that represent ports) qualifies as site-specific by any stretch of the imagination. 3) The Linux Filesystem Standard makes no provsion for self-compiled software. NOTE: FHS 2.1 states that /usr/local "is for use by the system administrator when installing software locally." This does NOT mean locally compiled (or else they would have said "compiled"), but instead has the same meaning as site-specific. /usr/local must be protected from overwriting when the system software is updated. For FreeBSD, this is then everything not found in /usr/src, since /usr/src is the source for the "system software", and is the only software updated during a system update (make world). Hence the FreeBSD organization is logical even by this consideration alone. It is equally logical for linux distributions to store everything in /usr, then, because nobody has any idea where the linux "system" ends and local software begins. The final result is that either way you look at it, the FreeBSD organization is intelligent and logical. For linux, the virtue of organization depends on how you look at /usr/local. If you follow the FHS word-for-word, then linux does a reasonable job by virtue of its lack of division between site-specific software and base software. If you follow a reasonable definition of site-specific, linux is ass-backwards. -- Andrew Hesford ajh3@chmod.ath.cx To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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