Message Oracle ORA-27123 - unable to attach to shared memory segment

ERRORunable to attach to shared memory segment
CAUSEshmat() call failed
ACTIONcheck permissions on segment, contact Oracle support

159989Oracle SGA for Reliant (32-bit) larger than 1.3 GB
84937ORA-7310 on HP-UX and Oracle 7.3.3 for SGA > 1 GB
651351BR tools on UNIX: Error due to executable permissions
92779Problems during the migration to 8.0.X
583861UNIX: Errors due to Oracle executable