Theodore Tso wrote:
On Wed, Jul 30, 2008 at 12:29:22PM -0500, Matt Domsch wrote:
2) those that report a 512-byte sector size, but are really a
4096-byte size, and the drive does the conversions and
read/modify/write. T10 and T13 are looking to add commands to
expose this different underlying physical sector size so the OS
could be aware of it. This is primarily being driven to mitigate
any problems that may happen with "legacy" OSs that are not aware
of the difference.
As usual, the biggest problem will be "legacy" userspace. For
example, most partition tools are still generating legacy partition
tables that look like this:
Disk /dev/sda: 255 heads, 63 sectors, 38913 cylinders
Nr AF Hd Sec Cyl Hd Sec Cyl Start Size ID
1 80 1 1 0 254 63 121 63 1959867 83
2 00 0 1 122 254 63 619 1959930 8000370 82
3 00 0 1 620 254 63 1023 9960300 615177045 05
4 00 0 0 0 0 0 0 0 0 00
5 00 1 1 620 254 63 1023 63 615176982 8e
Note the starting sector# for the first partition.....
- Ted
If I remember correctly, the MS Vista new alignment for data partitions
is on a 0 offset, 1MB aligned boundary. The support for 4096 byte
sectors is only for data partitions (not boot).
Array vendors, who consume a fair amount of drives, are most likely more
friendly to native 4k drives. The big fear from disk vendors is getting
a wave of returns from Best Buy, etc when people go and plug in a new,
native 4k drive into an old box....
ric
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