Date: Sat, 1 Dec 2001 00:46:04 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Tomas Svensson <tsn@gbdev.net> Cc: Josef Karthauser <joe@tao.org.uk>, freebsd-hackers@FreeBSD.ORG Subject: Re: SSH stalls (was: FreeBSD performing worse than Linux?) Message-ID: <200112010846.fB18k4i30686@apollo.backplane.com> References: <20011201032622.A18737@simba.systemteknik.net>
next in thread | previous in thread | raw e-mail | index | archive | help
I haven't been able to reproduce this. Two things, though... (1) are
you using a compressed ssh connection or an uncompressed connection?
It makes a big difference in regards to how ssh generates packet data.
'ls' contains a lot of repetitive data and compresses well.
(2) Also are you using an xterm or an aterm? aterm will skip terminal
data until the flow stops if it receives it quickly enough, not displaying
anything until it 'hicups' at the end. xterm will sync the display up
every so often when receiving a continuous stream. So if you are using
aterm it could appear as though the connection has stalled when, in fact,
it is actually running full bore and aterm is waiting for things to slow
down.
For example, when I run a program that spits out abcdefgh...zabcdefgh...
etc to the terminal, and run it on an aterm, it seems to stall every
so often. But if I run it on an xterm the output appears smooth.
-Matt
:JK> Is this the same problem that I experience on ssh connections between
:JK> my 5.0-current laptop and my releng_4 server? When I run an 'ls'
:JK> from the shell on large directories I get the response back block
:JK> delay block delay block. I assumed that it was a problem with
:JK> -current.
:
:I am quite sure that this is a problem introduced in OpenSSH v2.5 or
:earlier. When I upgraded a FreeBSD 4.2 box from OpenSSH v2.2.0 to a
:newer version (I don't remember exactly which one now) I noticed this
:stalling which had never appeared before. If I used SSH Inc ssh-2.4
:there was no stalling. It's not FreeBSD-specific either: I am
:trying this now on a NetBSD 1.5.1 that has OpenSSH v2.5.2 and if I
:do ten ls -l as fast as I can, I get 14 retransmitted packets and
:stalling. If I try the same with SSH Inc ssh-3.0.0 I get no
:retransmitted packets. Strangely enough I get no stalling on either
:sshd if I cat a 3 megabyte text...
:
:-Tomas
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200112010846.fB18k4i30686>