From owner-freebsd-questions Wed Apr 10 3: 9:41 2002 Delivered-To: freebsd-questions@freebsd.org Received: from rain.macguire.net (sense-sea-MegaSub-1-125.oz.net [216.39.144.125]) by hub.freebsd.org (Postfix) with ESMTP id 924BC37B400 for ; Wed, 10 Apr 2002 03:09:36 -0700 (PDT) Received: (from roo@localhost) by rain.macguire.net (8.11.6/8.11.6) id g3AA9Ia07574; Wed, 10 Apr 2002 03:09:18 -0700 (PDT) (envelope-from roo) Date: Wed, 10 Apr 2002 03:09:18 -0700 From: Benjamin Krueger To: Patrick Thomas Cc: dnelson@allantgroup.com, freebsd-questions@freebsd.org Subject: Re: overhead: sshd x 5 or screen ? Message-ID: <20020410030918.B4277@rain.macguire.net> References: <20020409151352.R59130-100000@utility.clubscholarship.com> <20020409225208.GF84522@dan.emsphone.com> <20020410005847.A4277@rain.macguire.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20020410005847.A4277@rain.macguire.net>; from benjamin@macguire.net on Wed, Apr 10, 2002 at 12:58:47AM -0700 X-PGP-Key: http://www.macguire.net/benjamin/public_key.asc Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Dan Nelson (dnelson@allantgroup.com) [020409 15:53]: > In the last episode (Apr 09), Patrick Thomas said: > > I am wondering what causes more overhead (disk, memory, and processor > > utilization): > > > > - running 5 concurrent ssh connections into a FreeBSD server > > > > - running 1 ssh connection into a FreeBSD server, and using `screen` to > > create 5 windows ? > > 5 sshs, because any output from session is encrypted and sent over the > wire, where with screen only output to the visisble window is sent. I'm not sure I follow the logic you're using here. How does being encrypted and sent over the wire reduce overhead? He did not mention whether this was a concern for the client or server, but assumably its server. I should say that all things being equal, a single ssh session with a single screen session is going to cause less load on the server. Consider that each network connection uses additional resources. 5 connections rather than 1. Each individual connection does utilize unique resources. Consider also that you need to encrypt 5 unique sshd sessions, rather than 1. Using a shared library will help reduce the memory footprint, but not the cpu usage. What you get are 4 extra network connections, and 4 extra sshd instances to replace 1 instance of screen. Somehow, I think screen is going to come out the winner. :) -- Benjamin Krueger "Life is far too important a thing ever to talk seriously about." - Oscar Wilde (1854 - 1900) ---------------------------------------------------------------- Send mail w/ subject 'send public key' or query for (0x251A4B18) Fingerprint = A642 F299 C1C1 C828 F186 A851 CFF0 7711 251A 4B18 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message