ORA-27092 if ULIMIT Small on Client OS User (Doc ID 165282.1)
do the actions documented in note.
If the issue persists, send me the output of ulimit -a executed by the "oracle" OS user.
you probably could not set the ulimit properly for the oracle OS user.
The following should be your limits (minimum) on AIX..
Shell limits
Soft File Descriptors at least 1024 KB
Hard File Descriptors at least 65536 KB
Number of processes (Soft) at least 2047
Number of processes (Hard) at least 16384
Soft STACK size at least 10240 KB
Hard STACK size at least 10240 KB; at most 32768 KB
Soft FILE size unlimited
Soft CPU time unlimited
Note: This is the default value.
Soft DATA segment unlimited
Soft Real Memory size unlimited
For AIX, it is the ulimit settings that determine process memory related resource limits , you can set either by using the smit utility or by editing the /etc/security/limits file...