Recently I worked with ASR on Exadata for multiple customers. ASR is a great functionality that enables your 'systems' to alert Oracle when hardware failures occur. Sun hardware is using ASM for sometime and since 2009/2010 this is also available for Exadata.

My goal is not to re-write the documentation so for general information I like to refer to this link.

So, where is this note about ? Well, it is about two things I experienced around setting up ASR. I like to provide my experience so others can be successful with ASR fast as well. (It is however expected that things will be updated in the latest documentation.)

First, imagine yourself configuring SNMP traps to be sent to ASR. In this situation be sure to not erase any existing SNMP Subscribers settings for example the subscription to Enterprise Manager Grid Control or whatever you already subscribed for.

So, when you have documentation stating to execute

"cellcli -e alter cell snmpSubscriber=(host=, port=)" 

be sure to add existing snmpSubscribers when they exist.

The syntax allows this:

snmpSubscriber=
((host=host [,port=port] [,community=community][,type=ASR])
[,(host=host[,port=port][,community=community][,type=ASR])...)

Second, when configuring SnmpSubscribers using DCLI you have to work with a slash to escape the brackets. Be sure to verify your SNMP settings after setting them because you might end up with a bracket in the 'asrs.state' file stating 'public\' in stead of 'public'.

Having the extra slash after the word 'public' of course doesn't help when sending SNMP-traps:

dcli -g dbs_group -l root -n "/opt/oracle.cellos/compmon/exadata_mon_hw_asr.pl -validate_snmp_subscriber -type asr"

cn38: Sending test trap to destination - 173.25.100.43:162
cn38: (1). count - 50 Failed to run "/usr/bin/snmptrap -v 2c -c public\ -M 
"+/opt/oracle.cellos/compmon/" -m SUN-HW-TRAP-MIB 173.25.100.43:162 "" SUN-HW-
TRAP-MIB::sunHwTrapTestTrap sunHwTrapSystemIdentifier s " Sun Oracle Database 
Machine secret" sunHwTrapChassisId s "secret" sunHwTrapProductName s 
"SUN FIRE X4170 SERVER" sunHwTrapTestMessage s "This is a test trap. Exadata 
Compute Server: cn38.oracle.com ""
cn38: getaddrinfo: +/opt/oracle.cellos/compmon/ Name or service not known
cn38: snmptrap: Unknown host (+/opt/oracle.cellos/compmon/)

All together ASR is a great addition to Exadata that I highly recommend. Some excellent documentation is written on the implementation details and available on MyOracleSupport. See "Oracle Database Machine Monitoring (Doc ID 1110675.1)"

Rene Kundersma
Technical Architect
Oracle Technology Services