[ltp] Re: Re: Re: Stress testing for undervolting

[TNKS]

Laurent Gilson wrote:

> What i did:
> - compress my debian with squashfs, load that image at startup into RAM,
> switch off the HD altogether.

Whoa.  I wasn't expecting that.  You know, everyone else talking about their
power consumption was talking about that absolute low in these idle moments
that are not necessarily the norm.  But if I'm reading this right, you'll
probably hitting that low on the average.  I didn't even think about using
squashfs like this.  I have some questions about your approach.

1) How much memory do you have?  I have 512MB, and I wonder if that's
enough.

2) How minimal of a Debian system did you squash?  Here's my current
system's sizes as reported by `du -si -s`:

0       cdrom
0       initrd.img.old
0       sys
0       vmlinuz
4.1k    mnt
4.1k    srv
17k     media
50k     tmp
58k     lost+found
521k    dev
970k    proc
4.4M    bin
4.6M    sbin
6.6M    root
12M     boot
13M     etc
69M     lib
176M    opt
633M    var
3.7G    home
4.1G    usr

I know some of these partitions are already virtual.  I just seems
impossible to fit a full scale system into 512MB and then still have room
to breathe.  How did you go about selecting what to squash on your system?

3) SquashFS is read-only, right?  So did you set up your system to have the
option (say from a grub menu) to boot up with a write-able Debian system? 
I don't know much about loading images into RAM (initrd?); the SquashFS
HOW-TO I found didn't address this explicitly.  

This might be a little more than I need to do -- especially if the
unwriteability of SquashFS gets in the way.  But it sounds neat.

- Sukant