Problem: WARNING: Limit of open file descriptors is found to be 1024. The OMS has been started but it may run out of descriptors under heavy usage. For proper functioning of OMS, please set "ulimit -n" to be at least 4096.
Example: $ emctl start oms Oracle Enterprise Manager Cloud Control 12c Release 12.1.0.1.0 Copyright (c) 1996, 2012 Oracle Corporation. All rights reserved. Starting WebTier... WebTier Successfully Started Starting Oracle Management Server... Oracle Management Server Successfully Started Oracle Management Server is Up WARNING: Limit of open file descriptors is found to be 1024. The OMS has been started but it may run out of descriptors under heavy usage. For proper functioning of OMS, please set "ulimit -n" to be at least 4096. Reason: Ulimit nofile parameter defines the maximum number of files that can be open by OS user. According to Enterprise Manager Installation guide, “Ensure that you set the soft limit of file descriptor to a minimum of 4096 and hard limit less then or equal to 16384.” which is mention in installation guide: http://docs.oracle.com/cd/E24628_01/install.121/e22624/install_em_exist_db.htm#BGBHFCAB Steps to fix that: 1. Check ulimit for nofile soft $ ulimit -Sn 1024
$ <OMS_HOME>/bin/emctl stop oms -all
$ vi /etc/security/limits.conf <UID> soft nofile 4096
$ <OMS_HOME>/bin/emctl start oms |