Linux on paperweight PCs
Created by Morbid_Angel
Created on 23 December 2000
Created for www.linuxhelp.net
Last modified
23 December 2000
Before we begin:
Before we begin I need to clarify a few things. The system you plan to use MUST HAVE DOS INSTALLED ON IT. If you do not have DOS or can not install DOS then stay home because you are out of gas and will not be able to perform the installation. You could, theoretically, place the HD into a working system and fdisk the drive and format it to DOS but you will need the copy or move programs from the exact version of DOS that you fdisk and format it to. This guide is intended for the more-than-casual linux user or the totally bored. Although my instructions are clear and concise enough that even a newbie to linux could perform it, you should be somewhat familiar with PC hardware and comfortable with command line configuration of the linux OS and DOS. This guide is intended as a baseline and may not work for everyone or every junk PC that you have holding your closet door open. This guide was designed for installing ZipSlack (Slackware linux 2.2.16 bloated kernel) linux on an old Toshiba Satellite 486/66 with 4M of ram and 500M hard drive. The only reason I did this was because I was bored, I had the time, I had the equipment and to see if it could really be done. There aren't many things you can do with a full distribution of linux on these boxes, however, you could perhaps select a smaller kernel precompiled and designed for the 486 (see "Afterthoughts" below) and trim up and customize the distribution after it's initial installation. 486 computers make great file servers (albeit very slow with many connections) or competent routers/gateways under linux but not much else. If you want your 486 to act as a router perhaps you should visit http://www.linuxrouter.org/
You would never ever want to actually work from this box or really even log into it except for necessary administrative purposes that can't be done in cron jobs. You should also avoid running multiple services (like Samba, Nfs, Dhcpd, etc.) on a single 486 with less than 4M of ram. If you can up the ram you might be able to combine two or perhaps 3 services but I wouldn't go hog-wild.
Absolute Bare-Ass Minimum Requirements:
- 486/33 Intel processor. You could go as low as 386, but why?
- 4M ram. Don't even think about anything less it WILL NOT WORK)
- DOS (already installed and bootable)
- 40M of hard disk space (after DOS) if you are installing from cdrom.
- 100M of hard disk space (after DOS) if you are installing by floppy.
- Lots of free time and patience.
Required To-Do and Downloads:
You have a few options if your machine does not have a cdrom drive or networking already:
- If you don't have a cdrom http://www.ibiblio.org/pub/Linux/distributions/slackware/zipslack/split/
- If you do have a cdrom and can burn ISO on another machine obtain the latest iso from Slackware
- If you have a Zip drive to put on the 486 then go here zipslack.zip
If you download the "split" (first option) then you will need at least two blank DOS formatted disks. Regardless of which version, you should have at least one floppy for copying files to and from the 486 and an already working system.
After you have downloaded the Slack that you need, you need to get the DOS version of PkWare (WinZip's grand-father for you younguns!) from here PK250DOS.EXE
If you have only 4M of ram you must get this file fourmeg.zip It creates an 8M swapfile that linux can access from the FAT partition. You should use this anyway, even if you have more than 4M of ram as it will greatly increase your system's performance.
Preparation:
Here I list the important things you will need to begin. You should perform all downloads in the previous section before going any further because at this point we are at the guts of things.
- Boot the 486 into DOS mode
- Copy the file(s) over (via floppy or cdrom) that you downloaded for Slackware into a directory like C:\TEMP. This can take forever if you are moving the "split" version floppy at a time (that's how I did it).
- Copy the PK250DOS.EXE file onto a floppy from your working system and then copy it to your 486 system via floppy.
- Once all the files have been copied over, you need to CD\TEMP and install PK250DOS.EXE.
- Use pkunzip <filename> to unzip your files. This should by default unzip them to C:\LINUX but check to make sure, otherwise manually CD \ then MKDIR LINUX and pkunzip the files into there. If you have the added benefit of Windows 3.1x then you can use the GUI to unzip them :)
Configuration:
With all of the files unzipped and located in the C:\LINUX directory, the pain will have already begun to numb you. Before you get all gung-ho about starting linux you must be prepared and make some very minor (yet critical) changes. You must CD\LINUX and EDIT LINUX.BAT. The instructions there are plain and simple. You uncomment (that is, remove the # sign from ...) the line that represents your hard drive DOS partition. In most cases this is /dev/hda1 because DOS/Windows assume the first primary partition.
After you uncomment the line, you should also append this "init 1", without the " " marks. This will force your system to load single-user mode and not try to start any silly services that you do not need right away. Don't worry, by default under ZipSlack runlevel 1 your filesystems are mounted read/write.
At this point you may run LINUX.BAT to start your linux system. Be patient -- it's DOS and it's a 486 box. Once the system starts at runlevel 1, you will automatically be given the # (root prompt) without password (I just love default security in some of these distributions!) First and foremost thing you should do is change root's password. If you don't, it has no password by default. Begin cleanup by using vi and edit /etc/inetd.conf and remove any services which you do not plan to run. I highly suggest that you remove all of them, then add ones after you get runlevel 3 going and then add the one or two you want. You should also visit /etc/rc.d and take a look at the run level scripts and make the necessary changes to stop the services from starting by default. These are usually rpc, network, dhcp, nfsd etc etc. From there, you should manually setup the aliases for eth0 (which should be automatically detected if using pcmcia nic on a laptop) and setup the static network.
With those minor changes completed, reboot the system into DOS and edit that file LINUX.BAT again but this time only remove the "init 1" entry. Run the LINUX.BAT file to start the system in runlevel 3 (multiuser mode) and you are ready to go. If you want the box to always start linux at boot, you may edit the AUTOEXEC.BAT file and have it CD\LINUX and then LINUX.BAT
Clean Up and Afterthoughts:
- It is safe to just power-off the system, although I do not recommend it. The filesystem is FAT and even if you blew something scandisk should bail you out.
- Log into the box directly from a console and not from telnet. This makes less strain on the old processor to maintain the connection.
- Use vi /etc/inittab and keep only one or two consoles active (agetty) to free up a little kernel space.
- Go to http://www.ibiblio.org/pub/Linux/distributions/slackware/kernels/ and try to find a better kernel for your 486 system. This default kernel is a bloated 2.2.16 (full) image. Your system will work so much better if you get a less-bloated and precompiled kernel. I wouldn't even think of trying to compile one on your new 486 linux system.
- You may edit or replace any system files in DOS mode. This means if you break something or files become corrupted, you may simply boot DOS and extract the single file from the original zip file(s) you kept in a temp folder or on floppy or on CD. Word of caution: if you edit a filename greater than 8 characters it will not save properly under DOS. These should always be edited with vi within the linux system itself.
- Take a look at the cron files for the system. Remove anything outside of log rotation. If you can and no how, use a remote machine for all logging and try to reduce the detail in which your systems log. This is of course not a security-minded option by limiting syslogd ... do that at your own risk!
- If you don't have more than 8M of ram and the swapfile, do not run the locate database update program (updatedb) or you will crash and burn. You should learn to use the find command under linux if you must absolutely locate a file on this system. Be warned it will take FOREVER if you search from /.
Morbid_Angel Dec 2000
"Come walk the line and you will burn with me"
http://mobid.mine.nu
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