Oracle Database Recommended I/O Size on EMC Unity

Question

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.

Davood Teymoori · Accepted Answer

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

DELL-Josh Cr · Answer

Hi,

The e-lab navigator could help with having the right configuration https://dell.to/3E0lvb9

You could try 32 or 8, I don’t see any specific official recommendations. Maybe someone else in the community can say what they have set it to.

Davood Teymoori · Answer

Thank you. Actually archive log LUNs generating large I/O size always and when other disk groups generating larger than 128KB, then LUNs response time will be increased.

I couldn't find root cause of generating large I/O size from archive log disks.

Unity

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