just noticed that there is a litte utility one can use for listing the operating resources ( semaphores, shared memory ) an oracle instance uses on a system. the nice thing about this utility is that you can use it even when the instance is down or crashed. this may be useful if some of the resources were not cleaned up and you need to identify which resources you may/must remove.
the documentation tells that this utility is available from 8i onwards.
$ORACLE_HOME/bin/sysresv --help /opt/oracle/product/base/18.104.22.168/bin/sysresv: invalid option -- - usage : sysresv [-if] [-d ] [-l sid1 ...] -i : Prompt before removing ipc resources for each sid -f : Remove ipc resources silently, oevrrides -i option -d : List ipc resources for each sid if on -l sid1 .. : apply sysresv to each sid Default : sysresv -d on -l $ORACLE_SID Note : ipc resources will be attempted to be deleted for a sid only if there is no currently running instance with that sid.
IPC Resources for ORACLE_SID "DB112" :
Oracle Instance alive for sid "DB112"