Single user mode requires access to the console. Your server's console port must be connected and configured to a LAN in order to work in single user mode. If you are not located close to the server (and the console is not connected), someone will have to perform the steps on the computer on your behalf.
Assuming that the server was not set up for remote management, there are a number of steps that will have to be done. There are two methods:
1. In the computer room, find a terminal with the proper null-modem cable and connect the terminal to the console port of the server. Or someone can bring in a laptop (older model that has a real serial port, or a laptop with a USB to serial converter) and connect to the console port. There are a bit more details that depend on what model of HP server you have.
2. Once connected to the serial port, set the terminal or laptop to 9600/8/N/1 and type CTRL-b to set the maintenance processor's prompt. Now you can see and set the console port's IP address, subnet and gateway values.
3. Connect the console LAN port to the network, ideally a special network reserved for maintenance (to improve security). Then test that the settings work by accessing the console port remotely.
Once you can connect to the console, you'll need to read a bit about the console commands to leave the processor maintenance processor and connect to the HP-UX console. The details depend on the model of your server. Now you are ready to shutdown and reboot into single user mode.
Or as mentioned above, you can stop all the applications and use fuser to find all the open files and terminate the processes that use them. Once that is done, you can umount /tmp, use lvextend followed by extendfs (on the raw lvol) and then mount /tmp.
Note that none of this required if you had purchased the OnlineJFS product which allow resizing of /tmp without single user mode.
Bill Hassell, sysadmin
