Exadata Database Machine is a complete, integrated rack system that contains both hardware and software for running Oracle Database.

Patch order

Patching it is done on a per-component basis and in general, in this order:

Infiniband Switches

Infiniband Switch patches may not be cumulative - needs to be checked in the README.

Storage Server Software

These patches are usually launched from compute node 1 using dcli and ssh to remotely patch each cell node.
Patches can be applied in a rolling fashion or standalone.
Rolling

./patchmgr -cells <cells group> -patch_check_prereq -rolling
./patchmgr -cells <cells group> -patch -rolling

Standalone

./patchmgr -cells <cells group> -patch_check_prereq
./patchmgr -cells <cells group> -patch

Check the log files:

Database server patch

These patches are specific to Exadata - so download the right ones.
They are, however, installed using the standard opatch mechanism.

CRS MLR patches