HP-UX System Administrator's Guide: Routine Management Tasks

emulators such as HP AdvanceLink (running on a Vectra PC) or X Window terminal
processes (such as hpterm and xterm). Also see “Other Terminal Problems” (page 161).
Unresponsive Terminals
There are many things that can cause a terminal not to respond (no characters are
displayed except, perhaps, those which are displayed by the terminal’s local echo
setting). Here is a procedure you can use to find many of them.
1. Check the status of the system.
Is the system still up? If not, you’ve probably found your problem. You will need
to reboot the system.
Is the system in single user state? If so, the only active terminal will be the system
console. Other terminals will not respond. You will need to switch to a multiuser
state. See the init(1M) manpage for more information on changing run states.
NOTE: To check what run state your system is in (from a working terminal) type:
who -r
The output will look something like:
. system boot Feb 10 07:10 2 0 S
The current state of the machine is in the field immediately to the right of the time
(third field from the right). For complete information on each of the fields, consult
the who(1) manpage.
2. Check to see if an editor is running on the terminal.
This is best done from another terminal. Issue the command:
ps -ef
Look in the column marked TTY for all processes associated with the terminal with
which you are having problems. For each entry, check in the column marked
COMMAND to see if the process represented by that entry is an editor.
If you find that an editor is running at the terminal, it is probably in a text-entry
mode. You will need to save the work and exit the editor. For directions on how
to do this, consult the manpage for the appropriate editor.
CAUTION: If you are not sure of the status of the work being edited, DO NOT
simply save the file and exit. You will overwrite the previous contents of the file
with unknown text. Save the work in progress to a temporary file so that both the
original and edited versions of the file are accessible.
3. Enter ctrl-q at the terminal keyboard.
Terminals frequently use the XON/XOFF protocol to start and stop output to them.
If output to the terminal was stopped because an XOFF signal (ctrl-s) was sent
Adding Peripherals 157