This post will provide a simple test case for the efficacy of creating and using an Oracle database cluster using NFS storage. The basic configuration will be shown, as well as the test case scenarios and results. A complete installation…
Category: RAC
Recreating diskgroup in an existing RAC
We created a diskgroup with normal redundancy, and were wasting half the space on the mirror as a result. We are completely striped and mirrored in EMC, so a mirror buys us no additional protection. We wanted to recreate the…
ltrace kills ocssd.bin which reboots node
The occsd.bin process is the core process which belongs to the Cluster Synchronization Service. This service is responsible for node membership decisions, so when it no longer exists, the server is rebooted. I was attempting to better understand the library…
Instance not restarting after failure in 11.2.0.3
I thought this was interesting. I always assumed that the RESTART_ATTEMPTS parameter of a cluster resource was only incremented after a failure to restart it. However, after developing an internal training course for our team, I noticed that after a…
ACFS install on CentOS
I run CentOS on a test cluster, and every time I patch it with a PSU or whatever, my ACFS installation is trashed as CentOS is not officially supported. To fix this, change the following section in $GRID_HOME/lib/osds_acfslib.pm… if ((defined($release))…
Instance state values in crsctl
As far as I can tell, the following values represent possible values for the state of instance as reported by crsctl status resource -t expressdb1:oracle:ecomm1:/u01/app/11.2.0/grid/bin# strings -a crsctl.bin | sed -n “16887,16910 p” Not Supported Any State Abnormal Termination Instance…
Linux firewall rules for RAC
Most notes on the Oracle MOS support site suggest disabling the firewall supplied in most Linux distros as managed by the iptables program. I think this is a bit drastic, and results in lazy thinking at best, and an exposed…
Why won’t my VIP start?
After restarting a test server, I found the RAC VIP would not start. This post is just a quick note as to how I troubleshot the problem, as well as its ultimate resolution. I frequently use the find -mmin 5…
Runtime connection load balancing issues in 11.2.0.2
We upgraded our largest and most important databases last month to 11.2.0.2 from 10.2.0.4. We had a few issues, most of which have been resolved. However, one that continued to plague us until yesterday is the apparent inability of any…
Querying load balancing information from the Load Balancing Advisory
I use what is below to periodically gather what the load balancing advisory posts. The data reflects the percentage of connections to distribute to each instance for a given service in a RAC. #!/home/oracle/local/bin/python import cx_Oracle, string conn = cx_Oracle.connect(mode…