fs_clone_sync_mode in EBS12.2.9

Hi,

Will the files in custom folder synchronize when we run the fs_clone with fs_clone_sync_mode=delta option? with the cp option it will copy the whole run file system to patch file system but what happens to the custom files when we use delta option?

Can anyone throw some light on the fs_clone_sync_mode=delta option in regards to customizations?

Thanks,

Suresh