Oracle Clusterware enables servers in an Oracle database Real Application Cluster to coordinate simultaneous workload on the same database files. The crsctl command provides administrators many useful capabilities. For example, with crsctl, you can check Clusterware health disable/enable Oracle Clusterware startup on boot, find information on the voting disk and check the Clusterware version, and more.
1. Do you want to check the health of the Clusterware?
# crsctl check crs
CSS appears healthy
CRS appears healthy
EVM appears healthy
2. Do you want to reboot a node for maintenance without Clusterware coming up on boot?
## Disable clusterware on machine2 bootup:
# crsctl disable crs
## Stop the database then stop clusterware processes:
# srvctl stop instance –d db –i db2
# crsctl stop crs
# reboot
## Enable clusterware on machine bootup:
# crsctl enable crs
# crsctl start crs
# srvctl start instance –d db –i db2
3. Do you wonder where your voting disk is?
# crsctl query css votedisk
0. 0 /dev/raw/raw2
# crsctl query crs softwareversion
CRS software version on node [db2] is [10.2.0.2.0]
STOP CRS
Connect as root and from ORA_CRS_HOME execute the following command on both servers
[root@vmractest1 bin]# ./crsctl stop crs
Stopping resources.
Successfully stopped CRS resources
Stopping CSSD.
Shutting down CSS daemon.
Shutdown request successfully issued.
Restart CRS on Both Nodes
[root@vmractest1 bin]# ./crsctl start crs
[root@vmractest2 bin]# ./crsctl start crs
Restarting CRS brought up all resources:
CRS Verion
$ crsctl query crs softwareversion
$ crsctl query crs activeversion
Monitor CRS Heath using OEM
$ cat /opt/oracle/admin/OEM/UserDefinedHostScripts/checkCRS.sh
#!/usr/bin/ksh
# OEM User Defined OS Metric. Script is called by OEM to monitor the health of CRSd on a particular node.
if [[ $(/ora01/oracle/product/crs_1020/bin/crsctl check crsd) = "CRS appears healthy" ]]
then print "em_result=0\nem_message=CRSd is healthy\n"
else print "em_result=1\nem_message=CRSd not responding\n"
fi
exit
