Correction. "0 size" in my message should be "0 nattch". The size is mostly
pagesize, 4k, not 0.
Also, very rarely, an entry in /dev/shm is a leftover not cleaned up properly
when the instance was shut down. So just because an entry /dev/shm/*<shmid>*
exists doesn't mean its shared memory segment definitely cannot be removed.
Since the name is like /dev/shm/ora_<SID>_<shmid>_<seq#>, you as a DBA know if
this SID is still running.
On Saturday, February 9, 2019, 10:22:52 AM CST, Yong Huang
Noveljic and Jeff,
The 0 size shared memory segments seen in `ipcs -m' are probably due to +ASM
and/or DB instances using AMM. Check /dev/shm/*<shmid>* to find out. Trying to
remove them with the Oracle command `sysresv -f' will give you a warning,
unlike ipcrm, which is a pure OS tool.