Ora-27103 Internal Error Svr4 Error 11 Resource Temporarily Unavailable [best] Jun 2026

set maxuprc=16384

| Cause | Explanation | |-------|-------------| | | ulimit -u too low, or kernel maxuprc / pid_max hit. | | Semaphore exhaustion | System-wide semaphore limits ( semmns , semmni ) too low. | | Shared memory limits | shmmax , shmall , or shmseg too restrictive. | | Memory pressure / swap full | No memory available for Oracle’s SGA or PGA allocation. | | Fork failure | Oracle tries to spawn a process (e.g., oracle binary) but OS cannot allocate new PID or memory. | | Stale semaphores / orphaned processes | Leftover from unclean shutdown. | | | Memory pressure / swap full |

Check the nproc (max user processes) and nofile (open files) limits for the oracle user in the /etc/security/limits.conf file. | Check the nproc (max user processes) and

ORA-27103: internal error (often accompanied by SVR4 Error: 11: Resource temporarily unavailable or shmseg too restrictive.

in init.ora:

ulimit -a

The most common cause is that the oracle user has reached its maximum number of allowed processes or threads ( nproc ).