I am working with an EMC XtremIO storage array that utilizes SSD devices that use a native 4 KB sector size instead of the traditional 512 B size. I am attaching an IBM AIX 7.1 server to the array. I had trouble getting AIX to assign a PVID to the LUNs and use them in a volume group until I changed the LUNs to emulate a 512 B sector size. As I understand it, there are benefits to using the native sector size if at all possible. Is there a way to get AIX to use these Advanced Format disks with their native sector size?
If you're using jfs, you should have no problem using a 4k block size. Usually, this stuff is taken care of by the multipath driver for the storage, as well as host emulation sometimes. Set your EMC storage's host emulation to "AIX" and make sure you installed whatever drivers they provided for AIX. That'll get everything aligned properly.