2010/2/14 Willie Wong <ww...@math.princeton.edu>:
> On Mon, Feb 15, 2010 at 01:48:01AM +0100, Frank Steinmetzger wrote:
<SNIP>
>>
>> action SS (1st) SS (2nd) SS+2 SS+4 SS+6 SS+8
>> -------------+----------+----------+----------+----------+----------+----------
>> untar portage 3m12.517 2m55.916 1m46.663 1m35.341 1m47.829
>> 1m43.677
>> rm portage 4m11.109 3m54.950 3m18.820 3m11.378 3m21.804
>> 3m12.433
>> cp 1GB file 0m21.383 0m13.558 0m14.920 0m12.813 0m13.407
>> 0m13.681
>
> Instead of guessing using this rather imprecise metric, why not just
> look up the serial number of your drive and see what the physical
> sector size is? If you don't want to open your box, you can usually
> get the information from dmesg.
hdparm capital eye works very nicely:
gandalf ~ # hdparm -I /dev/sda
/dev/sda:
ATA device, with non-removable media
Model Number: WDC WD10EARS-00Y5B1
Serial Number: WD-WCAV55464493
Firmware Revision: 80.00A80
Transport: Serial, SATA 1.0a, SATA II Extensions,
SATA Rev 2.5, SATA Rev 2.6
Standards:
Supported: 8 7 6 5
Likely used: 8
<SNIP>
>
> Only caveat: don't trust the harddrive to report accurate geometry.
> This whole issue is due to the harddrives lying about their physical
> geometry to be compatible with older versions of Windows. So the
> physical sector size listed in dmesg may not be the real one. Which is
> why you are advised to look up the model number on the vendor's
> website yourself to determine the physical sector size.
>
> W
> --
> Willie W. Wong ww...@math.princeton.edu
Very true...
Since this thread started and you help (me at least1) understand what
I was dealing with I got in contact with Mark Lord - the developer and
maintainer of the hdparm program. I was interested in seeing if we
could get hdparm to recognize this aspect of the drive. He was very
interested and asked me to send along additional info which he then
analyzed and decided that, at least at this time, even drives that we
__know__ are 4K sector sizes are not implementing any way of reading
it from the drive's firmware which is supported, at least in the newer
SATA specs. With that he decided that even for his own new 4K drives
he cannot do anything except either assume they are 4K and partition
appropriately or look up specs specifically as you suggest.
Currently I'm partial to the idea that all my sector starting
addresses will end in '000'. It's easy to remember and at most that
wastes (I think) 512K bytes between sectors so it's not much in terms
of the overall disk space. Just a couple of megabyte on a drive with 4
partitions.
= Mark
