Linux versus NetBSD
Despite the continuing onslaught of Windows, Unix is still a hugely popular operating system and is likely to remain so for a long time still to come. It is also one of the few Operating Systems that you can run on your Amiga without any sort of extra hardware or software emulation. Infact there actually 2 different versions of Unix available for the Amiga, so if you're considering installing Unix on your Amiga which one should you choose?

There are two main contenders, Linux and NetBSD. You may also have heard of other variations on the BSD theme, such as FreeBSD and OpenBSD and different distributions of Linux, such as Slackware, Debian or Redhat, however the differences between these versions is so small it probably won't affect most people. So that just leaves us with the two contenders for the Amiga Unix crown, Linux and NetBSD.

Linux originated on the PC in 1991, which means it's a mere babe compared to some of the other unix's which have been in existence since the late sixties! Linux was developed by Linus Torvalds and is not derived from any previous source of Unix, instead being designed from scratch to be Posix compliant. NetBSD was and still is developed by a large group of people, and originated from a flavour of Unix developed by the University of California, Berkeley (BSD stands for Berkeley Systems Distribution) in 1978. Development of BSD unix continued and NetBSD first appeared towards the end of the eighties.

So now you know their history lets see how they compare to each other and to the other Unix's available.

The first point to make about both Linux and NetBSD is that they are both highly stable. In a day and age where some modern Operating Systems seem to be unable go a whole day without crashing it is refreshing to know that it is not uncommon to find machines running Linux or NetBSD that have not been rebooted for weeks, even months and still are running perfectly.

As any of you who have ever used Unix before will know, the command syntax can be rather obscure and often requires cryptic arguments. To make matters worse different unix's have different commands, and different ways of organising essential operating system data. One of NetBSD's biggest advantages is it's origins with other flavours of Unix such as Solaris, Irix and HP/UX. Although the use of Linux is becoming more widespread in the commercial environment most of the large companies out there still use some kind of commercial unix.

NetBSD and Solaris have a lot in common, as fig 1 shows, Solaris is a System V unix, which evolved and draws heavily from the NetBSD development line. In it's favour Linux is extremely popular and has a much higher profile than NetBSD, especially on the PC where it is seen by many as the only alternative to NT.

In general, however, Linux comes across as a rather "unprofessional" operating system. Features that should be standard on a unix type operating system are missing, the Automount daemon and dump command to name but two. For home use this is not a problem, automount allows you to mount and unmount disks from other computers on-demand, and dump creates an image of a disk filesystem and is invaluable for backup purposes. Whilst most home users won't even notice these commands are missing their absence makes using Linux in a commercial environment more difficult then it's counterparts. Linux also falls down on it's disk sharing. Whilst the tools to mount remote disks on-demand are not present Linux can export (or share) it's disks to other machines. The method it uses for this is not as good as it should be and Linux can get very confused and refuse to share it's disks if the machine trying to access them has Virtual IP addresses. When linux can be persuaded to export it's disks it seems it's not getting it quite right. A solaris machine on our network complains bitterly when mounting disks from a Linux machine, even printing messages asking us to reinstall the server!

Another area where Linux falls down is in it's handling of swap and /tmp. All versions of Unix require you to set aside an area of disk space to be used as swap, unix's virtual memory. The majority of Unix's mount this swap space on /tmp, to be used as a RAM disk, the contents of which are lost every time the machine is rebooted. Linux appears to have no concept of a RAM based /tmp, and the default install of Linux created a /tmp directory on the root disk. As many programs and users expect to use /tmp as a temporary storage area, this is not only immensely stupid, but can also lead to problems when the root partition fills up with "junk" files.

NetBSD's certainly not perfect either, whilst it does come with an automount daemon (amd) as standard, the man page for amd.conf, the configuration file that determines exactly how it works is missing making using it almost impossible unless you can get a config files from somewhere else.

Software

There is a huge amount of pre-compiled software available for both Linux and NetBSD. Until recently NetBSD distributed these software packages in tar format, however in NetBSD1.3 a package format has been introduced allowing easy install of software and extra OS components. Linux also has a software package format, RPM (redHat package management), however rather strangely the package installer unrpm is not included as part of the linux distribution and must be downloaded from the internet (if you can find it). Of course if you can find a pre-compiled version of the program you want the beauty of Unix is that you can usually get the source code and compile it yourself. All of the popular window managers are available on both Linux and NetBSD, so there's no reason, cosmetically anyway, why you can't have identical Linux and NetBSD installations.

If you have access to the internet then both Linux and NetBSD have very well presented web pages containing all the information you'll ever need to download, install, configure and live with either Operating System. Both parties also have platform specific email d istribution lists which the website recommend you subscribe to if you need help with any aspect of NetBSD. I can't speak for the Linux list but the Amiga NetBSD mailing list certainly manages to solve most of the questions thrown at it. The only gripe I have about it is some of the answers can be a little too cryptic sometimes and if you ask what's considered to be an obvious question you'll all to often get a curt RTFM response!

Installing either operating system can seem quite a daunting task, as it involves re-partitioning disks and messing around with partition types, however comprehensive instructions are provided, although they can be confusing in places. However if you're thinking of installing either Linux or NetBSD on a PC then be sure to check out the hardware compatibility list on the relevant web site as only certain hardware is supported by each operating system. Amiga owners are fortunate in that both Linux and NetBSD support most of the Amiga hardware available. The only major omission at the moment is the PPC. Both the Linux and NetBSD web sites carry Amiga hardware compatibility list so you can check the suitability of your machine before you start to install.

The choice of which unix to install will depend largely on why you want to install unix in the first place. If it's just out of curiosity, or you want to use a piece of software that's not available for the Amiga then either will be fine. If you use Unix at work or college and want a similar system at home then you should try and install a version of unix as similar as possible to the one you are used to.

For use in a home environment I'd be perfect happy running either Linux or NetBSD, however for many of the reasons I've mentioned above, but mainly the fact that Linux is just too different from any other kind of Unix I'd find it very difficult to recommend Linux to anyone when they have the option of installing NetBSD. Linux's shortfallings are certainly in part to do with the problems and omissions I've already pointed out, but there's a whole host of other small things that, in my opition, give Linux a slightly "unpolished" feel to it. But then it's all a matter of taste, if you're used to working with Linux then you'll probably have exactly the same to say about NetBSD!

Note: On 10th November 1998 Schatztruhe released a CD-ROM containing the unofficial RedHat port of Linux for the Amiga. More details can be found here.

POSIX (Portable Operating Systems Interface) is the name used by group of standards sponsored by the IEEE that define a standard API for UNIX-like operating systems. POSIX.1 (IEEE Std1003.1-1990) standardizes the API for C. POSIX.2 (IEEE Std1003.2-1992) standardizes the Shell and Utilities. Virtual IP's. - a way of assigning more than 1 IP address to a network interface, allows a machine to be known as more than 1 name, e.g. uk.amigasoc.org and www.ezcgi.com RTFM Read The Manual, I'm sure you don't need me to tell you what the F stands for!