Set ulimit in Linux

Add these two lines to /etc/security/limits.conf file
username hard nofile 10240
username soft nofile 10240

Substitute your username
nofile indicates no. of open files parameter
10240 is the ulimit size
Set both hard and soft limits

Flush DNS in Solaris

1. Get PID using ps -ef | grep nscd
2. kill {PID}
3. Restart using /usr/sbin/nscd