Question:
Oracle Support on the note “Lun Size And Performance Impact With Asm [ID 373242.1]” and on the note “How to Prepare Storage for ASM [ID 452924.1]” say that in other things:

– Maximize the number of disks in a disk group for maximum data distribution and higher I/O bandwidth
– Size alone should not affect the performance of a LUN. The underlying hardware is what counts.
There is no magic number for the LUN size
– For larger LUNs it is recommended using a large ALLOCATION UNIT.

The provieder of the Storage EMC-Vmax say that the LUNS size can be 200 GB for database OLTP.

We believe that the premise or EMC_Vmax contradicts to ORACLE so instead of maximize the disks they pretend minimize the disks
of the DISK GROUP.

You believe that this is to be true for Storage EMC-Vmax.

Answer:
As mentioned in the document 373242.1.LUN size alone should not affect the performance.

Size alone should not affect the performance of a LUN. The underlying hardware is what counts. There is no magic number for the LUN size. Seek the advice of the storage vendor to recommend the best configuration from a raid 1 or 5 perspective for performance and availability since this may vary between vendors. Given a database size and storage hardware you have available, our best practice recommends creating larger LUNs (if possible to reduce LUN management for the sys admins) and create LUNs from separate set of storage arrays (drives) so that LUNs are not sharing drives if possible.

For larger LUNs it is recommended using a large ALLOCATION UNIT.