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