Date: Mon, 21 Feb 2000 07:24:12 -0800 From: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca> To: "Jeffrey J. Mountin" <jeff-ml@mountin.net> Cc: Tom <tom@uniserve.com>, stable@FreeBSD.ORG Subject: Re: Initial performance testing w/ postmark & softupdates... Message-ID: <200002211524.HAA53892@cwsys.cwsent.com> In-Reply-To: Your message of "Sat, 19 Feb 2000 03:53:42 CST." <3.0.3.32.20000219035342.009ce460@207.227.119.2>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <3.0.3.32.20000219035342.009ce460@207.227.119.2>, "Jeffrey
J. Mounti
n" writes:
> At 03:08 PM 2/18/00 -0800, Tom wrote:
> >On Fri, 18 Feb 2000, Daniel C. Sobral wrote:
> >
> >> Tom wrote:
> >> >
> >> > Not really. You could just use async updates instead of softupdates.
> >> > Or an OS that uses async updates. Write caching metadata is always
> faster
> >> > than re-ordering it intelligently.
> >>
> >> Softupdates reduces the number of writes needed. It can coalesce writes
> >> to the same block.
> >
> > Async updates are always as fast as softupdates, if not faster. You
> >should read the softupdates docs.
>
> As fast, but not safer.
>
> Can't recall the entire analogy, but Terry mentioned on -hacker a long time
> back something to the effect that softupdates is like having a seatbelt and
> an airbag rather than just a seatbelt, as well as a faster car too.
A paper by Gregory R. Granger and Yale N. Patt of the Departement of
EECS, University of Michigan entitled Soft Update: A Solution to the
Metadata Update Problem in File Systems discusses softupdate
performance v.s. asynchronous write performance. The difference wasn't
much, somewhere around 2-3%.
Regards, Phone: (250)387-8437
Cy Schubert Fax: (250)387-5766
Team Leader, Sun/DEC Team Internet: Cy.Schubert@uumail.gov.bc.ca
UNIX Group, ITSD, ISTA
Province of BC
"COBOL IS A WASTE OF CARDS."
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200002211524.HAA53892>