[Haifux] Login console freezes: Eli's weekly riddle

[Shachar Shemesh]

On 28/10/10 13:45, Eli Billauer wrote:
> Hello,
>
>
> The alert reader may have noticed that I've upgraded to 2.6.36. Which
> has caused a weird behavior with Fedora 12.
>
>
> I should start with sating, that after a couple of minutes, all weird
> things described below are over and forgotten, and everything runs as a
> clockwork. So let's see what happens immediately after bootup.
>
>
> The login screen appears and is responsive. I click my own user, and
> it's fine, but when I type the first character of my password, the GUI
> freezes for several seconds, and then becomes normal until I press
> another key on the keyboard. And so forth.
>
>
> While this is going on, logging in from ssh or a text console is
> extremely slow. In particular, when trying to ssh to the host, the
> prompt for password appears immediately (server is alive and kicking),
> but after entering the password it can take a minute or so until the
> login actually occurs (looks like someone holding some kind of lock?).
>
>
> Another interesting thing is, that if I log in first, and then get the
> GUI login stuck, I see the following while the GUI is frozen:
>
> (1) CPU usage remains idle.
>
> (2) A stupid echo loop in bash runs as fast as it normally does (no I/O
> issues, and CPU is free to run)
>
> (3) No special process jumps high on the "top" application.
>
>
> Any ideas? Any cool logfiles to look at, except for /var/log/{messages,
> gdm/*}?
>
>    
If both ssh and the graphical logins are slow, I would suspect PAM. Try 
ssh public key authentication and see what happens (I think that one 
bypasses pam). Also, see what /var/log/auth* have to say.

Shachar

-- 
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com