When you’re using OpenVZ container, occasionally you will encounter this error when you’re trying to su to root.
#su - su: cannot set user id: Resource temporarily unavailable
This is all about VPS the resources limitation in the container. A quick resolution to this issue by editing limit.conf as describe below or adjust them as needed.
#vi /etc/security/limit.conf #### add/change on these line below: * soft nproc 2047 * hard nproc 16384 * soft nofile 2048 * hard nofile 65536