Re: tools support for non-512 byte sector sizes

From: Pavel Machek
Date: Sun Aug 10 2008 - 16:03:31 EST


Hi!

> > - some disk makers have sort of agreed not to do that, and
> > expect forever to hide the larger underlying sector size
> > behind a virtual 512 (of course, this imposes alignment
> > restrictions, but that's a smaller problem)
>
> yes, this is happening also.
>
> There will be 3 types of disks eventually:
> 1) those that report a 512-byte sector size, and are really a 512-byte
> size. This is nearly all disks today.
>
> 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.

How is this going to work with journaling? This has nasty property
that if you are writing to sector n during powerfail, disk may also
kill sectors n-3, n-2 and n-1..... and that's bad right?

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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