Home Computing

Computers

I at present own three computers:

• A Pentium 4 1.8 MHz, with 256Mb of memory and a 40 GB disk. It is a dual-boot machine, running FreeBSD 4.7 in a 15 GB partition, and another operating system in a 20 GB partition. 5 GB is left over for experiments with other operating systems, and will probably be use for Linux one day soon. It has a CD-RW writer, a 10/100 Ethernet card, and a hardware modem that I have never used. I have not been able to get the on-board sound card and network cards to work with FreeBSD, so I added a PCI network card, and will investigate options for sound one day soon.
• A Pentium 120 that I have had since 1997, with 48 MB of memory, a 1.7 GB disk and a 10 GB disk. It also has a CD-RW writer and a hardware modem, and an Ethernet card. The CPU fan failed some time ago, and I didn't notice. So it now reports its speed as 100 MHz; it has presumably got a little old and tired. But it has been extremely reliable for the whole of its life. In fact, I upgraded it from a 486 in 1997, so the power supply has been running since 1993, almost continuously. (The power supply looks pretty dusty, and I have cleaned out the vents to some extent, but I expect it will fail before very long.) This machine also has a dual-boot set-up, running Windows 95 and FreeBSD 4.1.
  I now use it as a web server, using Apache. One minor innovation is a CGI script, in Perl, which generates a set of index pages for my collection of digital photographs. With this, I have only to save a new photograph in the appropriate directory, and it will appear automatically in the index page for that collection.
• A 486DX-33, with 20 MB of memory, and a 500 MB disk. It runs an early version of Linux (2.0 from memory), and has an Ethernet card and a modem. I got this machine from my sister-in-law, who said it was completely dead, and so she would not accept any money for it. She was quite right - it was as dead as a doornail, with a failed power supply. A used replacement later, and it was up and running Windows 3.1, to my pleasant surprise. I later installed Linux, and it has been running continously for over two years now.
• I also have access to a NEC Versa LX laptop, on loan from work. This is a Pentium 2 at 200 MHz, and 65 MB of memory. I have tried various operating systems on it, and it seems slower than I would expect. I don't much like laptops; the keyboards are inconvenient, and I am unable to use the pad that substitutes for a mouse. I far prefer a real mouse. Uh-oh. When I say a real mouse, I don't actually mean a real mouse. I mean a real computer mouse. It is currently running RedHat Linux 7.3, with the GNOME desktop. The installation was extremely easy, and this distribution comes with an impressive collection of software. The performance is simply dreadful on this machine, and I plan to try a light-weight window-manager; quite possible FVWM, which I used to use extensively, and always liked.

Networking

All four machines are networked together, using Ethernet and an SMC Barricade router, which isolates my home network from the outside world. The high-speed connection from our local cable service comes in to the Barricade router, which provides Network Address Translation, and gives me some confidence that hackers will have a relatively hard time. I could improve the protection with a little more work - one of the many things on my "to-do" list.

Getting the networking to do what I want has been more challenging than I expected. It proved quite easy to get to the stage where I could "ping" each machine from the other, but I had a learning curve to climb before I was able to share directories across the network using NFS, and to be able to telnet and ftp between them. It all came down to getting the configuration files right, and now I know how to do it, it seems easy.

I did try running Samba, which enables a FreeBSD or Linux machine to "pretend" to be an Windows NT server, so that it can serve files to Windows clients. I don't really have any need for this, and was never able to get it to work properly for a Windows 2000 machine.

I did have one puzzle to solve. Performance of the cable service was excellent, except for the first time that I tried to access "www.cnn.com" during a session. It took about 90 seconds to display the page. Other sites were fine, and subsequent pages from CNN were quick to appear. The answer,obtained by asking questions on the FreeBSD questions mailing list, was to disable IP6 in the kernel. This was easy to do, and completely solved this annoying problem.

Backing up

Now everything is set up the way I want, and seems to work very reliably. I use the Pentium 120 (100!) as a backup machine, and the home directories from the other machines are backed up automatically each night. Every week or so, I copy the contents of these backups to a CD, so I have a reliable record of all useful files that were on each machine, using a recording medium that cannot be affected by power surges or other electrical failures. I keep backup copies of the most critical CDs at an "off-site location" - that is, not in my home. Any files which are not in the home directory, and which I have modified, are copied to a place in the home directory structure just before the backup is made. This includes the many configuration files such as those in /etc. My method here is simple. I include a comment with my initials in any file I modify, and these are picked up automatically by the backup script, using grep. I am thus quite confident that I can reconstruct the state of a machine in an hour or two, even if its filesystems are completely destroyed. And yes - I have practised this.