Date: Wed, 26 Jan 2005 10:41:23 -0800 (PST) From: Arne "Wörner" <arne_woerner@yahoo.com> To: Zhihui Zhang <zzhang@cs.binghamton.edu> Cc: freebsd-fs@FreeBSD.ORG Subject: Re: ufs+softupdates / consistency Message-ID: <20050126184123.86908.qmail@web41215.mail.yahoo.com> In-Reply-To: <Pine.SOL.4.21.0501261317210.8299-100000@opal>
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--- Zhihui Zhang <zzhang@cs.binghamton.edu> wrote: > On Wed, 26 Jan 2005, Arne Wörner wrote: > > I would be glad, if somebody explains me, why ext2fs/async in > > Linux kernel 2.4.27 (KNOPPIX V3.7) is much faster (about 4 > > times faster) than a ufs with soft updates on the same slice of > > the hard disc? > > > > Is it due to consistency reasons? In case of a ext2fs/sync in > > my Linux setting Linux was about 4 times slower. > > > > Are we already trying to issue write order requests for the > > disc blocks (whose write order is arbitrary) sorted by sector > > number (in order to move the disc heads as less as possible)? > > The disc write cache could do that, but I disabled it in order > > to decrease the probability of inconsistency. > > > No file system is super for ALL benchmarks. Maybe you should > say something about your application, its access pattern, file > count, file sizes, read/write ratio, etc. > Ok Reading a special device (like /dev/ad0s2) in FreeBSD R5.3 is as fast as in KNOPPIX. But writing a single new file with big block size (32k-128k) and 1000 blocks is much different (depends on Linux/FBSD and sync/async). And I do not know now, why that is so. For further information see http://home.tiscali.de/cmdr_faako/ , if you want, please. -Arne Wörner __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com
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