Cleanup .patch_storage Directory under ORACLE_HOME

Now and then, DBA might experience disk space issues while patching and upgrading GI or DB. Under ORACLE_HOME there is a .patch_storage directory which uses huge disk space and stores all the patches already applied onto ORACLE_HOME.  Some are backup files and directories.

Following are the common methods to solve the disk space issues under ORACLE_HOME due to huge .patch_storage directory size.