Linked by theosib on Sun 14th Feb 2010 10:45 UTC
Linux

Recently, I bought a pair of those new Western Digital Caviar Green drives. These new drives represent a transitional point from 512-byte sectors to 4096-byte sectors. A number of articles have been published recently about this, explaining the benefits and some of the challenges that we'll be facing during this transition. Reportedly, Linux should unaffected by some of the pitfalls of this transition, but my own experimentation has shown that Linux is just as vulnerable to the potential performance impact as Windows XP. Despite this issue being known about for a long time, basic Linux tools for partitioning and formatting drives have not caught up.

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Brendan
Member since:
2005-11-16

Hi,

It's a DOS/Windows-compatibility thing you are trying to attribute to Linux. DOS/Windows has a problem, Linux just tries to be compatible.


No.

Very old disk drives used "CHS" (Cylinders, Heads, Sectors) instead of LBA. Due to limitations this didn't work for drives larger than about 500 MiB, so the industry shifted to LBA; and created a CHS->LBA translation scheme.

Due to BIOS limits, this CHS->LBA translation scheme usually uses "63 sectors per track", which is the highest number of sectors per track that the old BIOS disk interface can handle.

For performance reasons OSs make partitions that start/end on track boundaries (having a few sectors at the start or end of a partition that are on a track by themselves causes more disk head movement).

Basically what I'm saying is that the problem wasn't caused by *any* OS. The problem is caused by 30 years of backward compatibility (and the lack of foresight, from BIOS, disk and OS designers).

The ironic part is that the original IBM design supported floppy disks and hard drives with different sector sizes. It's unfortunate that this aspect of the original design was lost, and unfortunate that these new hard drives need to emulate 512-byte sectors to begin with.

-Brendan

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