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Archive for December, 2013

kill semaphore in Oracle Instance / remove shared memory from oracle instance

December 13, 2013 Leave a comment

if you have an issue after shutting down the instance you cannot start the instance it probably due to the fact that the semaphore of the instance is stil locked

#ipcs |grep oracle

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Set the ORACLE_SID

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sysresv is command to find symaphore attached to Instance.It will also shows shared memory address.

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To confrim

ipcs -a | grep oracle | grep <id> | grep <key>

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To clean up symaphore.

ipcrm -s 5996551   <- ID
ipcrm -M 0x9fcf02b4 <- key

confirm that the semaphore is killed

#sysresv

IPC Resources for ORACLE_SID “rmancpr” :
Shared Memory
ID              KEY
No shared memory segments used
Semaphores:
ID              KEY
No semaphore resources used
Oracle Instance not alive for sid “rmancpr”

 

 

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Performance tuning: HugePages in Linux

December 13, 2013 Leave a comment

Performance tuning: HugePages in Linux

Good article on pythian about huge pages in Llinux

 

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