Date: Mon, 28 Dec 2009 17:41:26 +0100 From: Pieter de Goeje <pieter@degoeje.nl> To: freebsd-current@freebsd.org Cc: Alexander Motin <mav@freebsd.org>, Miroslav Lachman <000.fbsd@quip.cz>, Thomas Backman <serenity@exscape.org>, freebsd-arch@freebsd.org Subject: Re: File system blocks alignment Message-ID: <200912281741.27179.pieter@degoeje.nl> In-Reply-To: <4B38A4DE.2040507@FreeBSD.org> References: <4B349ABF.2070800@FreeBSD.org> <4B389D60.7000005@quip.cz> <4B38A4DE.2040507@FreeBSD.org>
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On Monday 28 December 2009 13:30:22 Alexander Motin wrote: > Miroslav Lachman wrote: > > Alexander Motin wrote: > >> Thomas Backman wrote: > >>> On Dec 25, 2009, at 11:58 AM, Alexander Motin wrote: > >> |>> Recently WD released first series of ATA disks with increased > >> > >> physical > >> > >>>> sector size. It makes writes not matching with 4K blocks inefficient > >>>> there. > >>> > >>> They don't expose this to the OS, though (not by default, anyway), > >>> but chop it up into 8 512-byte sectors for compatibility reasons. > >>> Just thought I'd point that out - I'm not even sure if you can get > >>> them to *not* do the compatibility thing and expose 4k-sized sectors. > >> > >> Latest ATA-8 specification allows drive to report both logical (512B) > >> and physical (4KB) sector sizes. ada driver able to fetch and report > >> that info to GEOM. If these drives not reporting it yet (are you really > >> sure?), it is only question of their firmware. > > > > There is an article about 4k sectors > > http://www.anandtech.com/storage/showdoc.aspx?i=3D3691 > > > > It is completely hidden to OS in first versions. > > Thanks for the link, but all I see there is "but at this point there=92s > no such tool". IMHO it doesn't meet it is not reported. > > We just need somebody with that drive to run on it `camcontrol identify` > from the fresh system and report what he sees. I've just ordered one of these disks. I expect it to arrive in a couple of= =20 days. Will let you know what it says when I have it :) =2D Pieter
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