Date: Tue, 13 Nov 2012 18:46:51 -0600 (CST) From: Robert Bonomi <bonomi@mail.r-bonomi.com> To: freebsd-questions@freebsd.org, rfg@tristatelogic.com Subject: Re: Advanced Format Drive ? Message-ID: <201211140046.qAE0kpw0084082@mail.r-bonomi.com> In-Reply-To: <4073.1352844470@tristatelogic.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> From: "Ronald F. Guilmette" <rfg@tristatelogic.com> > Subject: Re: Advanced Format Drive ? > Date: Tue, 13 Nov 2012 14:07:50 -0800 > > > And while we are on the subject... Has anybody ever down any analysis > (i.e. benchmarking) to find out if -f 4096 is even the best number for > a modern high(er) capacity drive? I'm just sort-of wondering if 8192 > or 16384 might be better. As long as the fragment size is a power-of-two multiple of the media sector size, there is no significant performance difference. The only case where a larger fragment size makes any difference is heavy random i/o on files where the larger fragment size translates to one less level of indirect block in the meta-data. Larger fragment sizes also make for more 'waste' space in the 'used' part of the disk, assuming random file sizes. And reduce the space savings gained by _not_ writing 'holes' to disk. For these reasons, in general, small is better. > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201211140046.qAE0kpw0084082>