demarem@clutx.clarkson.edu (Michael J. de Mare,222 Hamlin,,2684041) (03/20/91)
I have Minix 1.5 running on my AT clone with about 42 Megs of hard disk and 512K RAM (I use a HD partition for the root device). It works quite well for me, and I usually leave it up nonstop (I reboot on average about once a month, usually to install modification I made to the kernel, I test them on similiar machines in the public access terminal rooms to protect my hard disk). Recently I installed it on a 386 in an AT box. I did not install the 32-bit kernel patches, so it was more or less identical to what is running on my 286 (less my mod's). I was quite shocked that for most of the sort of thing that I do, it RAN SLOWER ON THE 386! Later I decided that the difference must be that I have an IDE controller in my system and a tolerably fast hard disk, but this brings out an important point: the I/O architecture is much more important for performance than the CPU speed. It is my opinion that there will never be an efficient implementation of *IX on the the current crop of PC's using what is (currently) standard controllers/disks. I think that MINIX ought to have drivers that take advantage of the super-SCSI boards out there to let it act more like a real UNIX system. I do not think that virtual memory/disk swapping is important given the current price of memory though. My next point is that Minix needs a multithreaded filesystem. I have three terminals on my Minix system, one hardwired, the other a modem. When more then one thing involving the fs goes on, there are intolerable waits on the other terminal to do anything. The problem is that the filesystem can only deal with one request at a time, I think a multithreaded filesystem coupled with device drivers that work with HD drivers that order requests for speed would make Minix a good enough system for most 2-3 user applications. The drawback, of course, is that people would have to purchase advanced controllers and hard disks to use this capability. Now that I am done griping, I would like to than Dr Tanenbaum and all the other people working on Minix for an excellant operating system at a reasonable cost. Seeing as I learned to program on a PDP 11/34 running Unix rev 6, Minix is the first operating system that I have really liked in a long time. I also would like to thank them for the excellent documentation on the source code which makes the chore of finding the right bit to modify easy, even fun. Keep up the good work. Mike de Mare Crime does not pay ... as well as politics. -- A. E. Newman