I have several users connecting via a Windows-based SSH\telnet client. The previous sysadmin used FacetTerm to allow certain users to switch between multiple "windows." I'm told there are AIX-native ways to do this but I work with what I inherited.

Originally, many users were still connecting via telnet. I know this isn't usually a big risk on a private network but I'd still prefer SSH for the encryption. However, the users that have been switched to SSH have to be very careful about how they end the session. If they simply disconnect or close the client without logging off, they are unable to log back in. Here's a specific example:

I've tried killing processes associated with their username but that doesn't seem to free them up. So far, the only successful fix has been a reboot. I'm comfortable on the command line but I'm a long, long way from a real expert and, in particular, I'm clueless when it comes to anything dealing with ttys. Any input at all will be a help and an education.

Now that I think about it, both the title and my explanation are probably misleading.

Each user is assigned specific ttys. If they don't log out properly, it is *only* their ttys that are busy. I think "Assigned pty cannot be opened." is the informative part of the error.

Hmmm,
looks like accounting info got out if sync...
man fwtmp

All the best