Re: RAM distribution catch-22, 2 old P1 generation PCs

[Andrew Daugherity <andrew_(_dot_)_daugherity_(_at_)_gmail_(_dot_)_com>]

The problem with a flash disk is its limited number of write cycles. 
This is usually on the order of 100000 writes/cell, which makes it
suitable for mass storage, but obviously quite unsuitable for a swap
drive.  So you would need to have enough RAM that you would never need
to swap.

The CF-ATA adapters plug into your IDE channel and have the CF disk
appear as a normal IDE disk (wd0), so there should be no issue there,
except for the lack of swap.  You would probably also want to
configure syslogd, pflogd, etc. to buffer logs in memory and only
write to disk once per hour or so (assuming this is possible), or
alternatively have another machine running syslogd as a log server and
have the logs sent there, or simply nfsmount /var/log, /var/run, etc.

As far as how much RAM, you probably want to stick to 64MB in the
Pentium system, as more will probably exceed the cacheable limit of
the chipset, meaning all RAM above 64MB cannot be cached by the L2
cache, resulting in slower access to that RAM.  Of course, if you're
running stuff that needs more memory, uncached RAM is still much, much
faster than swapdisk.


-Andrew


On Mon, 14 Feb 2005 01:55:17 +0100, Jens Ropers <ropers_(_at_)_ropersonline_(_dot_)_com> wrote:
> Many thanks for your reply and suggestions -- only this had me somewhat
> puzzled:
> 
> On 14 Feb 2005, at 01:17, Stuart Henderson wrote:
> 
> > With enough RAM that you don't need to swap, and switching off the
> > HD at idle (and reducing crontab) or replacing it with 8-16mb CF and
> > an IDE adapter) you would significantly drop power use and increase
> > the firewall's life expectancy than using normal HD.
> 
> If I'm not misunderstanding you, you're proposing that I use a Compact
> Flash card in lieu of an actual hard drive? Surely 8-16MB can't be
> enough for an OpenBSD 3.6 install? Or are you proposing using custom
> kernel?
> 
> cheers,
> -- ropers