Re: IA32 chroot
Le Sat, Oct 15, 2005 at 08:40:55AM -0400, Steve Dondley écrivait/wrote:
> I'm reading the amd64 howto. I've never used chroot on a computer.
> I'm getting a little intimidated by this chroot stuff.
>
> Before I get ahead of myself, I should mention that I'm going to
> running just a basic LAMP server (with a few other apps like VIM,
> webmin, and SquirrelMail) on my 64 bit machine. No X windows,
> openoffice, or anything like that. Will I even need to worry about 32
> bit apps?
Probably not (but I am not sure, not having lot of AMD64 experience).
And you could choose to go into 32bits chroot later - just reserve
some [small] disk space for it (maybe a spare partition would make
things simpler).
According to your needs, all your programs (Apache,Mysql,PHP,
Vim,Perl, Webmin, SquirrelMail, exim4 or postfix, etc...) exist in
native 64 bits. Maybe you would want some 32bits chroot for running
stuff which don't exist in 64 bits (on a desktop, it could be some
macroflash plugin for mozilla, and openoffice, on a server, I don't
know but maybe some JVMs run more stably on 32 bits only?)
>
> Second, for my own edification, can someone please help me
> conceptualize why I would need chroot to run some 32 bit applications?
> Having never seen chroot in action, I've never been able to grasp
> what exactly chroot does for you. I know it makes another directory
> the root but...so what?
Read the man page of chroot(2) system call. Once a process (usually
the chroot(8) command) changes its root and its working directory, it
and all its child processes sees only the new root as a
filesystem. Hence this root should be populated with approriate files
(eg /lib/ld.so, /lib/libc.so, /etc, /dev/null, /dev/zero and probably
many others required files). So in essence, theses process run in a
different file space... which can be a 32 bits "distribution"
FWIW, I'm running my Turion laptop in 64 bits only
Debian/Sid. http://starynkevitch.net/Basile/msi_s270_linux.html and I
noticed that linux 2.6.13.4 with the latest BIOS (3.70 MSI) is much
more stable than previous stuff (my laptop crashes only once a day;
the problem is probably ATIX200 chipset related)
Regards
--
Basile STARYNKEVITCH http://starynkevitch.net/Basile/
email: basile(at)starynkevitch(dot)net
8, rue de la Faïencerie, 92340 Bourg La Reine, France
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