Server refused to allocate pty (NetBSD PV guest but probably related to PV Linuxes as well)
If you faced this kind of error on your terminal
login as: ****
Keyboard-interactive authentication prompts from server:
| Password for ****@hostname.tld:
End of keyboard-interactive prompts from server
Server refused to allocate pty
especially often in PV guest of XEN this means that there are no available terminals you can be attached to.
Fix is easy, and for NetBSD is just one command
mount_ptyfs ptyfs /dev/pts
This creates pseudo filesystem mounted on /dev/pts
$ df -h
Filesystem Size Used Avail %Cap Mounted on
/dev/xbd0a 8.9G 118M 8.3G 1% /
/dev/xbd2a 148G 90M 140G 0% /var
/dev/xbd1a 58G 5.4G 50G 9% /usr
kernfs 1.0K 1.0K 0B 100% /kern
procfs 4.0K 4.0K 0B 100% /proc
tmpfs 4.0G 4.0K 4.0G 0% /var/shm
ptyfs 1.0K 1.0K 0B 100% /dev/pts
Every next login when "normal" terminal - tty is not available you will be redirected to /dev/pts
$ w
2:30PM up 2:33, 3 users, load averages: 0.10, 0.18, 0.08
USER TTY FROM LOGIN@ IDLE WHAT
login pts/2 172.19.100.107 2:30PM 0 w
login ttyp0 172.19.100.107 2:24PM 0 ksh
login ttyp1 tmux(40).%0 11:56AM 5 cvs -d:ext:anoncvs@anoncvs.NetBSD.org:/cvsroot -q update -d -P -rne