su command fails with resource temporarily unavailable

SYMPTOMS

~]# su - grid
Last login: Mon Feb 19 12:15:34 CST 2024 on pts/0
su: failed to execute /bin/bash: Resource temporarily unavailable

CAUSE

The maximum number of user processes exceeded the limit.

~]# ps h -Led -o user | sort | uniq -c | grep grid

SOLUTION

Increase the nproc values in /etc/security/limits.d/97-oracle-database-11g-limits.conf.

~]# cat >>/etc/security/limits.d/97-oracle-database-11g-limits.conf <<EOF
grid   soft   nproc    16384
grid   hard   nproc    16384
EOF