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Low Memory Installation

From Martin Skjöldebrand on Sun, 17 Jan 1999

HI again,

Many thanks for you fast reply. And apologies if you got two messages - I forgot to remove your e-mail adress in the second one.

Hi,

I'm trying to install Debian from floppies on my spare lap-top.

It's an old machine, an Compaq Contura 486/ 25 with 4 MB RAM and 80 MB HDD.

The installation goes well (mostly - it complains that the swap space cannot be initialized but it still is used, swapon during startup later on goes well). But after rebooting I get various memory errors.

The latest being 'bash fork: Cannot allocate memory' when trying to do anything on the machine.

This sounds more like there is a disk error (bad block or some such) that's somewhere in the area where you're trying to create your swap partition.

That would explain both the initialization failure (which I presume is an error message from the installation script's 'mkswap' routine) and the bash errors.

I've read and re-read the floppy install on low-memory systems. I've expanded the swap space to about 20 MB (should be enough) but it still complains about the memory problem.

If the error is near the beginning of the swap file/partition --- then you'll keep getting it now matter how much disk space you add to the partition.

Adding swap space sorted out a few error messages I got in the first attempts. But you suggestion solves the problem of it not going away. I partitioned the drive with the option of checking for bad blocks (I think I did this the last time. I've rerun the install one time too many. Is there a difference between this and mkswap -c?).

Try invoking the mkswap command (which should be somewhere in your startup files) with the -c option (to check for bad blocks).

I'll boot off of a start disk and run it as root, then. I suppose you meant that. (As I can't get in on the system to do anything meaningful at all as the only reaction I get is the error message).

Any ideas? Is it possible to run Debian on a 4 MB RAM machine?

I don't know. That's cutting it pretty thin. I certainly wouldn't use 'bash' on a 4Mb system --- 'bash' is hardly a lightweight shell. Try 'ash' --- which is a simpler and smaller shell that's designed for use on rescue floppies, etc.

You'll certainly want to compile a custom trimmed kernel (on another system) for use in such a constrained setting. I wouldn't think that the Contura's were so old that you can't find additional memory for them. Bumping that up to 8 or 16 Mb will make a huge difference in what you can do with that laptop.

Yeah, I've had the thought myself - but Compaq memory usually is extremely overpriced. Especially for older machines. At least IMHO.

Again, thanks for your suggestions and your fast reply. I'll look into it.

Cheers,

Martin Skjöldebrand
Sys admin, archaeologist, web designer

Copyright © 1999, James T. Dennis
Published in The Linux Gazette Issue 38 March 1999

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