On Thu, 2009-03-12 at 14:20 -0400, Matthew Wilcox wrote: > From: Matthew Wilcox <matthew@xxxxxx> > > New features are being added to the READ CAPACITY 16 results, so we > want to issue it in preference to READ CAPACITY 10. Unfortunately, some > devices misbehave when they see a READ CAPACITY 16, so we restrict this > command to devices which claim conformance to SPC-3 (aka SBC-2), or claim > they have features which are only reported in the READ CAPACITY 16 data. > > The READ CAPACITY 16 command is optional, even for SBC-2 devices, so > we fall back to READ CAPACITY 10 if READ CAPACITY 16 fails. We're going to have to do something about the scary error messages on SBC-2 supporting drives, this is what mine say (and this is after mkp's chat reduction): sd 1:0:1:0: [sdc] READ CAPACITY(16) failed sd 1:0:1:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE sd 1:0:1:0: [sdc] Sense Key : Illegal Request [current] sd 1:0:1:0: [sdc] Add. Sense: Invalid command operation code sd 1:0:1:0: [sdc] 71096640 512-byte hardware sectors: (36.4 GB/33.9 GiB) sd 1:0:1:0: [sdc] Write Protect is off sd 1:0:1:0: [sdc] Write cache: disabled, read cache: enabled, supports DPO and FUA sd 1:0:1:0: [sdc] READ CAPACITY(16) failed sd 1:0:1:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE sd 1:0:1:0: [sdc] Sense Key : Illegal Request [current] sd 1:0:1:0: [sdc] Add. Sense: Invalid command operation code sdc: sdc1 sdc2 sdc3 sd 1:0:1:0: [sdc] Attached SCSI disk What they're saying is that they don't support READ CAPACITY(16) which is perfectly legal for SBC-2 conforming devices which don't support protection information ... like almost every modern disk in the field. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
