[TAG] need information about sylpheed-claws
Benjamin A. Okopnik
ben at linuxgazette.net
Wed Apr 13 08:42:08 MSD 2005
On Tue, Apr 12, 2005 at 03:18:59PM -0600, Jason Creighton wrote:
> On Thu, 7 Jul 2005 21:18:06 -0400,
> "Benjamin A. Okopnik" <ben at linuxgazette.net> wrote:
> > ``
> > ben at Fenrir:/tmp$ dd if=/dev/zero bs=1GB count=1|bzip2 > foo.bz2
> > ben at Fenrir:/tmp$ ls foo*
> > -rw-r--r-- 1 ben ben 722 2005-07-07 21:05 foo.bz2
> > ben at Fenrir:/tmp$ mutt -s 'Hi, Karl-Heinz!' -a foo.bz2 kh at somewhere.com < /dev/null
> > ''
> Perhaps apropos of the swap space discussion elsewhere, I tried your
> command, and...
> ~$ dd if=/dev/zero bs=1GB count=1|bzip2 > foo.bz2
> dd: memory exhausted
> ~$ dd --version
> dd (coreutils) 5.2.1
> Written by Paul Rubin, David MacKenzie, and Stuart Kemp.
I've got the same one.
> Copyright (C) 2004 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions. There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> I have 128 megs of RAM, plus 150 or so of swap. Looks like dd tried to
> grab the whole thing at once. You either have a different version of dd
> or a much nicer setup than me.
Heh. Not necessarily nicer, but I tend to do some large-scale
stuff once in a while, so I tend to prefer to configure it by using a
Mack truck's front bumper as a model.
ben at Fenrir:~$ free -tk
total used free shared buffers cached
Mem: 515464 320600 194864 0 23032 117328
-/+ buffers/cache: 180240 335224
Swap: 1951888 0 1951888
Total: 2467352 320600 2146752
In other words, 512MB of RAM and a couple of GB of swap (none of which
is being used at the moment, but I've just rebooted after configuring a
shiny new 220.127.116.11 kernel.)
> So for people without that much VM kicking around, you could use:
> ~$ dd if=/dev/zero bs=1M count=1024 | bzip2 > foo.bz2
> 1024+0 records in
> 1024+0 records out
> You'd have to use "bs=1MB count=1000" to make the size match Ben's
Right on both counts. I wasn't expecting people to actually *do* this,
just to become aware of it. It _is_ an interesting sort of thing to play
with, though - 1GB shrunk to 700-some _bytes?_ Wow.
> > If you project that kind of compression ratio to, say, 1TB or so, you
> > can see how it might fry an AV utility's little brain... and if Mr.
> > Cracker is lucky, it might totally fill up the partition as well.
> That's just *evil*, Ben. I wish I'd thought of it.
[grin] Me too. I was just riffing off something that a poster on Bugtraq
said a while back; he didn't approach the problem exactly this way, but
it was implicit in his idea. A clever fellow, that one.
* Ben Okopnik * Editor-in-Chief, Linux Gazette * http://linuxgazette.net *
More information about the TAG