Date: Fri, 31 Jan 2003 12:40:28 -0800 (PST) From: Julian Elischer <julian@elischer.org> To: phk@freebsd.org Cc: Steve Byan <stephen_byan@maxtor.com>, freebsd-fs@freebsd.org, tech-kern@netbsd.org Subject: Re: DEV_B_SIZE Message-ID: <Pine.BSF.4.21.0301311240030.45015-100000@InterJet.elischer.org> In-Reply-To: <31671.1044043107@critter.freebsd.dk>
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On Fri, 31 Jan 2003 phk@freebsd.org wrote: > In message <Pine.BSF.4.21.0301311144370.45015-100000@InterJet.elischer.org>, Ju > lian Elischer writes: > > > > > >One thign I thought of is that it is not uncommon to 'dd' an entire > >filesystem from one partition to another. > >If we create a filesystem that is 'aligned' and we copy it to be > >'unalligned', we'd have a sudden performance drop for no immediatly > >obvious reason. What was one write, would become a 2-sector read, > >modify and 2-sector write. Especially when copying from one failing > >drive to another with slightly different characteristics. > > If you run dd without bs=ALOT you deserve bad throughput. I'm talking about the performance of the filesystem after it's been moved. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > phk@FreeBSD.ORG | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message
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