Re: [openMosix-general] OpenMosix with MPICH over LTSP Question

[Peter C. <pe...@ll...>]

On Mon, Jan 26, 2004 at 05:22:51PM -0600, Sean The RIMBoy" wrote:
> On Mon, 26 Jan 2004, Peter Cordes wrote:
>=20
> >  sshd is much slower than rshd, BTW.  It has to do a lot of crypto to
> > authenticate a connection, so startup times are _way_ higher with ssh.
>
> Agreed.  One thing you can do to help a little is to use blowfish for your
> crypto.

 That only helps if your symmetric cipher is CPU limited.  I'm talking about
the RSA (or DSA) authentication stuff when the connection is made.  The time
to encrypt a packet with the shell command line you want is negligible, even
with 3des, compared to the connection setup time of ssh.

 As you say, it's useful when transfering a lot of data.  I've seen the
suggestion that turning compression on can actually decrease CPU usage,
because there will be less data to encrypt!

>  I make sure to use it when I'm transferring files (scp -c
> blowfish).  Better yet, you'll die() if you transfer a large amount of
> data off of an SGI and don't use blowfish.  Of course, it's all relative,=
=20
> your SGI won't die (though some should) but you'll be waiting a long time=
=2E =20

 I still have Cipher Blowfish in my /etc/ssh/ssh_config, but I haven't
changed the Ciphers  line (for ssh2), so it will use AES-128 for ssh2
connections.  Isn't Rijndael (sp?) supposed to be pretty fast?  (It was the
winning AES candidate.)

--=20
#define X(x,y) x##y
Peter Cordes ;  e-mail: X(peter@cor , des.ca)

"The gods confound the man who first found out how to distinguish the hours!
 Confound him, too, who in this place set up a sundial, to cut and hack
 my day so wretchedly into small pieces!" -- Plautus, 200 BC