Re: [tlug] Slooooooow down: SSH

[Dave M G <dave@example.com>]

TLUG,

Today it occurred to me I could try another test to see if I could
narrow down what was going on.

Now that I have my wireless network set up, I could test SS connections
from my laptop as well. Yeah, I know I could have plugged an ethernet
cable into my laptop and not needed wireless particularly, but swapping
cables where my router is is a pain.

Anyway, the problem so far has been a basic slow down between Mythbuntu
(server), and Main machine (client).

With my laptop in play, I thought I'd see what it's like going laptop
(client) -> Mythbuntu (server), and laptop (client) -> Main machine
server. (I could also try Mythbuntu (client) -> Main machine (server),
but I think I learned what I need to from using my laptop.)

Long story short: The connection is slow from any machine to any other
machine.

One possibility is that this means it might be something to do with my
router, though I think that's very unlikely because I have not changed a
setting on the router in years. (The slowness problem happened well
before I installed the wireless, and even when I was setting up the
wireless, I didn't even once open the interface for my main router. Just
saying in case it might seem obvious that the new wireless router might
be an issue).

I think it's more likely that since I set up all three machines, use
*buntu on all of them (Ubuntu on two, Mythbuntu on one), that it's most
likely that I've set up something common to all three. Or that *buntu
set up something that got installed on all three that I didn't switch off.

In any case, even though I was hoping the problem would be localized to
my Mythbuntu machine, I at least know that this is more general.

Another thing I've learned by crawling around web forums is that other
people have reported symptoms very similar to mine. Slow SSH
connections, sometimes seemingly faster after rebooting all machines,
but eventually in inevitably getting slow again. (As I write this, a
click on an interface via SSH takes four seconds to register).

However, all people seem to report that putting "UseDNS no" in ther
sshd_config file cured the problem for them completely.

I came across one poster who said that he believed that a corrupt MythTV
database was somehow causing slowness on his SSH. I posted on the MythTV
mailing list and asked, and the response seems to be that's extremely
unlikely. In any case, my MythTV database passes all tests and appears
not to be corrupt. And since the problem is now also apparent between my
laptop and main machine, I think I'm discounting the possibility.

That's all for now. Still searching the web for that silver bullet that
will kill this bug.

-- 
Dave M G