Reporting Logical Block Size==Physical Block Size

Mike Berhan mikeb at
Wed Dec 18 07:00:26 PST 2013

* From the T10 Reflector (t10 at, posted by:
* Mike Berhan <mikeb at>
I'm working on a device whose logical block size of 4096 equals its physical
block size.  In reviewing the Read Capacity 16 structure, the low nibble of
byte offset 13 indicates:
0 = One or more physical blocks per logical block (i.e. not reported)
n > 0 = 2^n logical blocks per physical block
My issue is that I would like a way for this device to definitively state
that the logical size equals the physical size.  The value of '0' doesn't
work.  Block Limits VPD page doesn't appear to have an option either.  Other
than providing a vendor unique method, is there an SBC defined location
where the device can report its logical block size equal to its physical
block size?  Thanks in advance.
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at

More information about the T10 mailing list