[TAG] System V or BSD?

[Mike Orr]

On 12/2/05, Adam S Engel <bartleby.samsa at verizon.net> wrote:
> I was hunting down  a "fugitive" process and accidently hit the BSD
> command ps aux (thinking it was an accident because I'm using Mandriva,
> which I thought was based on System V) and received something like this:
>
> ~ 495 --> ps aux | head -5
> USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
> root         1  0.0  0.0   1560   476 ?        S    Nov30   0:00 init [5]
> root         2  0.0  0.0      0     0 ?        SN   Nov30   0:00
> [ksoftirqd/0]
> root         3  0.0  0.0      0     0 ?        S<   Nov30   0:00 [events/0]
> root         4  0.0  0.0      0     0 ?        S<   Nov30   0:00 [khelper]
>
> But then, just for the hell of it, I hit the System V command, ps -ef
> and got this:
>
> ~ 494 --> ps -ef | head -5
> UID        PID  PPID  C STIME TTY          TIME CMD
> root         1     0  0 Nov30 ?        00:00:00 init [5]
> root         2     1  0 Nov30 ?        00:00:00 [ksoftirqd/0]
> root         3     1  0 Nov30 ?        00:00:00 [events/0]
> root         4     1  0 Nov30 ?        00:00:00 [khelper]
>
>
> I thought most Linuxes, particularly the "big ones" like Fedore, Debian,
> SuSE, Mandriva, were based on System V.  Even so, my MacOSX, based
> loosely on BSD, will not accept the ps -ef command.  Can a system
> (Mandriva in this case) be comprised of both?   The rc.init files seem,
> from what I recall from Redhat, to be System V.

See "man ps".  The 'ps' Linux uses has two sets of command-line
options to please everybody.  There are also verbose long options, and
two sets of output formats.

Linux generally follows the System V "style" but deviates whenever it
feels like it.  The network stack is closer to BSD's.    The init
system is not part of "Linux" (the kernel) but is chosen by each
distribution.  Most distros use System V style, and even those that
don't like Slackware have compatibility directories so that
vendor-compiled commercial programs can be installed without too much
hassle.  However, the init strategy is one of the most varying things
between distributions.

> Can anyone tell me the major difference between FreeBSD and
> Linux?  I've heard that FreeBSD is known for its security and other
> network capabilities.

Some people say BSD's network stack can handle a higher load.  But
both systems are widely used in high-performance mission-critical
situations, so the difference is a bit academic.  Isn't Linux being
used for rocket control somewhere?

Linux comes in a wide variety of flavors from user-compiled hacker
systems (Gentoo) to turnkey Windows clones (Linspire), with RPM/DEB
distros in between.  BSD sticks to the user-compiled route.  BSD also
tends to have less support for new hardware, and last time I checked
it had an incompatible disk-partitioning scheme, making dual booting a
problem.  But if a user-compiled distro appeals to you and you like
the BSD traditions, FreeBSD would be worth looking into.  That seems
to be the most popular one for new users, although NetBSD and OpenBSD
are also free and would be worth comparing.

--
Mike Orr <sluggoster at gmail.com>
(mso at oz.net address is semi-reliable)