su command hangs

[Rick Stevens]

Ruby Domalanta wrote:
> 
> Hi Guys,
> 
> Is there anybody who are using QVT as emulator and use SSH1/SSH2 to 
> logon to their linux box? Basically, we have a RH AS3 and we've been 
> trying to ssh'ed to it using QVT. It went well but when I issued su 
> command it hangs. BTW, our box is using PAM.
> 
> I even also tried to used Putty as emulator and logon using ssh. It was 
> successful even with su command. So seems the problem lies  between the 
> QVT/ssh or maybe the PAM. This really gives me a lot of headaches 
> because I am new to Linux. Please help!

I'm not familiar with QVT, other than the old Qume RS232-based
stand-alone terminals.  If that's what you have, then that smells like a
reset problem.  First, do a couple of things:

1. Before using the "su" command, type in "echo $TERM" to see what
kind of terminal the system is treating QVT as.  If they don't match,
see if you can tell QVT to emulate what the system _thinks_ it is.  If
not, you may have to set the TERM variable to match what QVT is, and I
don't know if the system actually has one that will work.  There are a
bunch of entries for the Qume terminals.

2. Did you use "su" or "su -"?  "su" alone simply does the UID/GID
change and shouldn't cause a lockup.  "su -" acts like a full login,
complete with terminal reset sequences being issued.

3. You can try to see if the session itself is hung or if it's just the
terminal.  Try entering the commands: "reset" or "stty sane" (they
probably won't echo) and see if things come back.  It may be that the
"su" is sending an escape sequence that your emulator doesn't handle
gracefully.
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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-          When all else fails, try reading the instructions.        -
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