> From: "Ronald F. Guilmette" <[email protected]> > 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. > [email protected] mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "[email protected]" > _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[email protected]"
