#61 Memory usage jumps to 100% when copying files to vfat drive

[Andrew J. Montalenti]

I have an 80GB hard drive in an external enclosure with
an Oxford Semiconductor SBP2 bridge board. The Oxford
Semiconductor bridges are supposedly fully supported by
the ieee1394/ohci1394/sbp2 kernel modules, and indeed I
can get access to my drive after all the proper probing
and mounting.

The 80GB hard drive is now and has always been a large
fat32 partition. Reason being I needed it to work fully
with my Windows desktop, my Apple notebook, AND my
Linux desktop (the only fs lowest common denominator in
all these OSes is fat32). I read on an ieee1394 mailing
list that one should NOT mount vfat drives through the
1394 modules because you will get "poor performance."

Regardless, I decided, performance schmorformance, I
just need to have access to the drive; I'm not going to
be benchmarking it, just throwing files onto it
occasionally. So I use it and it works fine for awhile.
But then I notice something weird. The Memory Monitor
Applet I loaded into my gnome panel was at 100% usage
(and I have 512MB of RAM!) I tried opening up
gnome-system-monitor and it listed that all my memory
was used, but didn't show any big memory hogs in the
process list. So I reboot and my memory is back to
normal on boot. I mount my firewire drive and memory is
normal. I copy a file to my firewire drive and I
literally watch the memory climb from 23% usage to 100%
in a matter of 15 seconds. When I umount my firewire
drive, rmmod the corresponding modules, and physically
DISCONNECT my firewire drive, my memory usage REMAINS
at 100%, and I am unable to alter it without a reboot.

In fact, my memory is at 100% usage right now. Here is
the output of vmstat (I read somewhere it may be helpful):

procs -----------memory---------- ---swap-- -----io----
--system-- ----cpu----
r b swpd free buff cache si so bi bo
in cs us sy id wa
0 0 1280 6376 18904 375848 0 0 390 341
192 576 11 1 87 0

It may be also useful to note that I am running
Libranet 2.8... I posted a message similar to this one
on the Libra user forum:
http://forum.libranet.com/viewtopic.php?t=1631

My libra install is pretty much the way it came "out of
the box." So this is what I am running ;)
http://libranet.com/features.html

Thanks for your time,
-Andrew