From time to time I'm getting an OSError exception with the message 'out of pty devices' when calling pty.openpty() (it's happening when a bunch of instances of my scripts run concurrently).
What is the limit that I'm hitting? How can I get around this?
CentOS 5.6, Python 2.4
In my Ubuntu Linux, the max number of open ptys is given by:
cat /proc/sys/kernel/pty/max
This value is configurable in:
/etc/sysctl.conf
All this info, and much more can be found in:
man pty
Same issue is raised when devpts is not mounted, usually in chroots, to mount devpts device type:
# mount -t devpts none /path/to/chroot/dev/pts
来源：https://stackoverflow.com/questions/8561121/troubleshooting-oserror-out-of-pty-devices