[oracle@dbserver OPatch]$ ./opatch prereq CheckConflictAgainstOHWithDetail -phBaseDir /setup/psu/11.2.0.1.1/9352237/ Java HotSpot(TM) Server VM warning: You have loaded library /u01/app/oracle/product/11.2.0/db_1/oui/lib/linux/liboraInstaller.so which might have disabled stack guard. The VM will try to fix the stack guard now. It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'. java.lang.UnsatisfiedLinkError: /u01/app/oracle/product/11.2.0/db_1/oui/lib/linux/liboraInstaller.so: /u01/app/oracle/product/11.2.0/db_1/oui/lib/linux/liboraInstaller.so: wrong ELF class: ELFCLASS64 (Possible cause: architecture word width mismatch)