The issue was related to “max_sectors_kb” value on Linux. I think that EMC should add recommendation value to best practices or connectivity guide for EMC Unity. Also read my blog post about that: I/O Block Size Best Practice on EMC All Flash/Hybrid Flash Array and Linux (Physical And Virtual) - Davoud Teimouri - Virtualization and Data Center
Hi, What is recommended value for I/O size for Oracle Database on EMC Unity Hybrid/All-Flash array? db_file_multiblock_read_count is set to 16 but we have large I/O size on storage and this situation increasing service time and response time. The I/O size is near to 1MB. 
Oracle Database Recommended I/O Size on EMC Unity