>>>>> "ag" == Andrew Gabriel <andrew.gabr...@oracle.com> writes:
ag> Having now read a number of forums about these, there's a
ag> strong feeling WD screwed up by not providing a switch to
ag> disable pseudo 512b access so you can use the 4k native.
this reporting lie is no different from SSD's which have 2 - 8 kB
sectors on the inside and benefit from alignment. I think probably
everything will report 512 byte sectors forever. If a device had a
4224-byte sector, it would make sense to report that, but I don't see
a big downside to reporting 512 when it's really 4096.
NAND flash often does have sectors with odd sizes like 4224, and (some
of) Linux's NAND-friendly filesystems (ubifs, yaffs, nilfs) use this
OOB area for filesystem structures, which are intermixed with the ECC.
but in that case it's not a SCSI interface to the odd-sized
sector---it's an ``mtd'' interface that supports operations like
``erase page'', ``suspend erasing'', ``erase some more''.
that said I am in the ``ignore WD for now'' camp. but this isn't why.
Ignore them (among other, better reasons) because they have 4k sectors
at all which don't yet work well until we can teach ZFS to never write
smaller than 4kB. but failure to report 4k as SCSI 4kB sector is not
a problem, to my view. You can just align your partitions.
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