06-11-2011 08:33 PM
/sys/block/sdh/device/model: WDC WD20EARS-00M /sys/block/sdh/queue/physical_block_size: 512 /sys/block/sdh/queue/logical_block_size: 512 /sys/block/sdh/alignment_offset: 0I am worried that the OS kernel is going to think the drive writes only need to be aligned on 512-byte boundaries instead of 4k. Is there some way I can make the drive correctly report its physical sector size, as apparently some other WD drives (and many non-WD drives) do?
06-11-2011 09:16 PM
it is ok, that's 'advanced format', the firmware emulates a 512 byte sector disk.
thw WD20EARS is a 512 byte logical / 4K physical harware sector drive, that's it.
just do not forget to align the partitions in order to avoid the performance penality of having
the partitions not aligned.
06-11-2011 10:01 PM
06-12-2011 12:33 AM
06-12-2011 02:20 AM - edited 06-12-2011 02:20 AM
Thanks for the info! I used smartctl under Linux and viewed the IDENTIFY DEVICE hex data. The model number correctly appears in words 27-46 as per the ATA8 spec, so it would seem I am looking at the correct data.
However word 106 (physical/logical sector size) is zero, as are words 117-118 (words per logical sector).
You mentioned in the linked thread that this information is optional, so I guess WD chose to omit it from these drives for some reason. This is a shame, as one of the reasons why I chose this drive was because I wanted to try out these 4k sectors to see how my system behaved. Maybe I should just return the drive? Seems a shame when there's nothing mechanically wrong with it, but I'm guessing there's not much likelihood of getting a firmware update any time soon to fix this... :-(