Error Messages (U) A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Unable to attach to shared memory segment Do you encounter either of these errors -- unable to attach to shared memory segment unable to determine size of shared memory segment Check permissions on your $ORACLE_HOME/bin/oracle file. You may need to set the sticky bit.First, run an ls -l $ORACLE_HOME/bin/oracle. It should look like this --openlink> ls -l /$ORACLE_HOME/bin/oracle -rwsr-s--x 1 oracle dba 33692568 Aug 18 2009 oracle If it does not, use the chmod command to alter the permissions like this --chmod 6751 oracle