From owner-freebsd-stable Sat May 5 15:42:33 2001 Delivered-To: freebsd-stable@freebsd.org Received: from ptavv.es.net (ptavv.es.net [198.128.4.29]) by hub.freebsd.org (Postfix) with ESMTP id 7DA4437B424 for ; Sat, 5 May 2001 15:42:29 -0700 (PDT) (envelope-from oberman@ptavv.es.net) Received: from ptavv.es.net (localhost [127.0.0.1]) by ptavv.es.net (8.10.1/8.10.1) with ESMTP id f45MgBc24741; Sat, 5 May 2001 15:42:11 -0700 (PDT) Message-Id: <200105052242.f45MgBc24741@ptavv.es.net> To: Nick Sayer Cc: Doug Russell , stable Subject: Re: soft update should be default In-reply-to: Your message of "Sat, 05 May 2001 09:31:09 PDT." <3AF42ACD.5000500@quack.kfu.com> Date: Sat, 05 May 2001 15:42:11 -0700 From: "Kevin Oberman" Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Date: Sat, 05 May 2001 09:31:09 -0700 > From: Nick Sayer > Sender: owner-freebsd-stable@FreeBSD.ORG > > That may be the original intent, but cheap IDE drives let you turn on > write caching, and they're for sure not battery-backed (nor do they > attempt to store enough power at power-off to write back the cache with > the remaining rotational latency or any such trickery). They lie about it. > > Write caching is evil unless you specifically know that it's being > battery backed. 99.44% of the time, that's not the case. An obvious exception is the laptop. I always turn on write cache on my laptop as I know that it has a LONG battery backup. For a worst-case type of operation (dd), I get 4x faster writes with write-cache enabled on my laptop. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message