Re: thinkpad digest for Mon, 22 Sep 1997

[phr@netcom.com (Paul Rubin)]

	From: "Paul Khoury" <pkhoury@loop.com>

	Also, does anyone here (besides myself) use an ATA Flash RAM
	card for use as extra storage?

I have a 10 meg card and have been thinking of getting a larger
card if/when I can afford it.  At present I'm not using the flash card
since it was in my Omnibook 300 which now has a broken screen :(((.
I can read the files from it under w95 but I prefer to run Linux.

The idea of using flash is not as much to have "extra" storage as to
spin down the hard disk and have a machine I can use and access files
on without the noise of a rotating disk.  My machine is a 755cx with
40MB of ram.  What I'm thinking of doing is one of:

  1) configure Linux to have 20 mb of regular ram and a 20 meg
     ramdisk.  At boot time, load the ramdisk with the most commonly
     used system programs (for me, that means emacs :)) and spin down
     the disk.  My user files would be stored on the flash card.  Then
     I can edit, run "ls", etc. all from the ramdisk without needing
     the HD, and when I write out files they go to the flash card so I
     still don't need the HD.  In case of a crash, my user files are
     still saved in flash; the ramdisk contents get lost, but that's
     ok since they're just copies of system programs that are on the
     HD.  I'm not sure how I'd set this up--maybe I'd have to put a
     tiny root file system on the flash card, and mount the ramdisk to
     some directory on it.

  2) Give up on the ramdisk idea since it probably involves a lot of
     configuration hassle.  Buy a much bigger flash card (85 MB
     Sandisk card = about $1000) and put a normal small system 
     installation on it including user files.  85 MB was a lot of
     space even for a hard disk not that long ago :).  Unfortunately
     I haven't got the cash for this now.
 
In both cases, the hard disk would be NFS auto-mounted so when I need
a less commonly used file, it would spin up.  All the directories in
my normal search path (/bin, /usr/bin, etc.) would be present in
ram or flash, but the less commonly need programs in them would be
replaced by symlinks pointing to the HD.  That way if I mis-type a
command name, the HD won't spin up after the filename isn't found
in the ramdisk.

Comments are welcome, especially ideas about how hard it would be to
carry out idea #1 above.  I'm not that much of a Linux configuration
whiz.  

Note, one hassle with flash cards is their writing speed is a LOT
slower than hard disks.  The current regular Sandisk cards write at
around 300K/sec which is 2x cd-rom speed.  The new "double density"
cards are even slower at around 75k/sec (floppy speed), though they
come up to 160 MB (!) in a type 2 pcmcia card.  But since I'd normally
just be writing out small files, the slow speed is probably ok.