screen is a utility available on Linux that create virtual terminals.

In practice, it enables user to run command on a remote device (ie. typically via a SSH session) that will continue running even if the connection is interrupted.

Screen is broken on QNAP TS-253E¶

Unfortunately, by default (tested right after installation), screen doesn't work on QNAP systems (tested on QTS 5.0 and QTS 5.1).

When running screen, it fails with an error such as

# screen
/var/run/utmp: No such file or directory
Cannot find termcap entry for 'xterm-256color'

Fix screen¶

Create the missing file and some symlinks.

touch /var/run/utmp
ln -s /usr/share/terminfo/x/xterm-xfree86 /usr/share/terminfo/x/xterm-256color
ln -s /usr/share/terminfo/x/xterm-xfree86 /usr/share/terminfo/x/xterm-color

Alternative fix¶

Rather than create symlinks, one can make screen use existing termcap entry with the env variable TERMINFO.

TERMINFO='/usr/share/terminfo/' screen

However, this solution has proven more cumbersome and less reliable.