Although Linux will install and run on something as
small as a 386/16 with no hard disk (you boot
from floppies), you cant really
expect to run your business on it. To do useful work, you have to be installed
on a hard disk and have at least 4MB of RAM
for text-based applications and 8MB
if you are running X-Windows.
However, this, too, is pushing things a bit, and you probably can only have one user
working effectively. Consider an extra megabyte per user for text
applications and 2MB for X-Windows, or slightly less
if the users will all be using the same applications (because the text
segments will be shared).
The amount of hard disk space you need is a completely
different matter. Its not as easy to come up with a rule of thumb because each
site will want to have a different set of applications. The basic UNIX
utilities and programs will fit in less than 20MB. However, there is not much
you can do with that. On the other end of the scale, I installed the Caldera
Network Desktop with the Internet Office Suite onto a 500MB partition
a complete RedHat distribution. Today, distributions like
SuSE Linux come with up to seven CDs, which will
obviously take up several gigabytes when fully installed. I then had to
reinstall to make the partition
larger because I ran out of space. In the middle
is my laptop, on which I have a 100MB partition
and almost a complete Linux installation (no X-Windows).
Most of the commercial distributions list a
few example installations and how much hard disk space you will need. Every
commercial product I have seen lists how much space you will need. The products
that are bundled with a Linux distribution also tell you how much the OS
will/can take. It is therefore fairly easy to get an idea of how much
space you will need.
For the most part, if you have a standard PC, Linux
will run on it. By "standard" I mean that the components are common
brands and types, there are no clones and the hardware has been on the market for
more than a week.
Linux is most commonly available for Intel machines.
However, a few commercial versions are available for the DEC Alpha processor.
There are also versions for the Motorola 680x0 as well as the PowerPC, SPARC,
and MIPS (how many am I missing?). The best thing to do is check the Hardware
HOWTO to see whether the hardware you have is supported.