Editing FreeBSD Reference (section)

= pty problems =

Not a problem after 4.x

Each jail system, and each customer system on each jail, has 256 /dev/ptyXX files on it.  This is because each login on the underlying system, even if it is a customer logging into their jail, takes up a pty. So, the underlying system needs to have the maximum number of ptys it can (256).

You might think that no jail user would ever use more than the default number of ptys, which is 32, so why do we up the number of pty /dev nodes in each jailed system as well ?  The reason is that the device node used for each login starts at zero, and increments for _every_ login on the machine, whether it is a login by a customer or a login to the underlying machine.

So, the very first login session a customer might initiate could be using /dev/pty54, not just /dev/pty1.

This issue should never come up - you just need to make sure FreeBSD filesystem images are created with all 256 ptys.  However, if a customer ever complains that they cannot log in, and get some kind of "no more ptys" or "out of ptys" errors, you need to go to that machine, and make sure there are 256 ptys in the underlying /dev, _and_ that there are 256 ptys in the jailed /dev.  If there are not, go to the dev directory in question and run:

<pre>/bin/sh
for i in 1 2 3 4 5 6 7 ; do sh MAKEDEV pty$i ; done</pre>
 
This will never come up if the dump-files you use with jailmake are made properly - the only other reason it could come up is if a customer accidently deletes his /dev/pty nodes, which has never happened.