Database Software

We're building a new non-RAC 11.2.0.3 system on x86-64 RHEL 5.7 with ASM diskgroups stored on a NetApp device (don't know the model # since we are not storage admins but can get it if that would be helpful). The system is not a data warehouse--more of a hybrid than pure OLTP or OLAP.

In Oracle® Database Storage Administrator's Guide 11g Release 2 (11.2) E10500-02, Oracle recommends using allocation unit (AU) size of 4MB (vs. a default of 1MB) for a disk group be set to 4 MB to enhance performance. However, to take advantage of the au_size benefits, it also says the operating system (OS) I/O size should be set "to the largest possible size."

http://docs.oracle.com/cd/E16338_01/server.112/e10500/asmdiskgrps.htm

Since we're using NetApp as the underlying storage, what should we ask our storage and sysadmins (we don't manage the physical storage or the OS) to do:

* What do they need to confirm and/or set regarding I/O on the Linux side
* What do they need to confirm and/or set regarding I/O on the NetApp side?

On some other 11.2.0.2 systems that use ASM diskgroups, I checked v$asm_diskgroup and see we're currently using a 1MB Allocation Unit Size. The diskgroups are on an HP EVA SAN. I don't recall, when creating the diskgroups via asmca, if we were even given an option to change the AU size. We're inclined to go with Oracle's recommendation of 4MB. But we're concerned there may be a mismatch on the OS side (either Redhat or the NetApp device's OS). Would rather "first do no harm" and stick with the default of 1MB before going with 4MB and not knowing the consequences. Also, when we create diskgroups we set Redundancy to External--because we'd like the NetApp device to handle this. Don't know if that matters regarding AU Size.

Hope this makes sense. Please let me know if there is any other info I can provide.