I was hoping someone could help me understand what happened with my Ubuntu server.

I had an issue with it acting odd, I won't go into detail but I restarted the server with this command:

shutdown -r now

When it came back up, I attempted to use screen and was given this error:

No more PTYs.
Sorry, could not find a PTY.
[screen is terminating]

I found this website which told me this:

http://en.positon.org/post/%5BScreen%5D-No-more-PTYs-Sorry-could-not-find-a-PTY

You have to change /dev/ptmx file permissions:

# ls -l /dev/ptmx 

crw-r--r-- 1 root root 5, 2 nov 18 23:28 /dev/ptmx

# chmod a+w /dev/ptmx

# ls -l /dev/ptmx 

crw-rw-rw- 1 root root 5, 2 nov 18 23:34 /dev/ptmx

This didn't resolve my issue since I was already at:

crw-rw-rw- 1 root root 5, 2 nov 18 23:34 /dev/ptmx

Same problem.

So I found this post:

https://superuser.com/questions/302235/no-more-ptys-when-trying-to-start-screen

So, I did what the answer suggested, which was:

# mount devpts /dev/pts -t devpts -o mode=620

And it worked fine.

Anyone know what happened, why, and what the devpts did to fix it? I'm completely lost on this one.

Thank you!