From owner-freebsd-hackers Tue Apr 24 2:50:43 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from ringworld.nanolink.com (ringworld.nanolink.com [195.24.48.13]) by hub.freebsd.org (Postfix) with SMTP id 1BDC037B423 for ; Tue, 24 Apr 2001 02:50:41 -0700 (PDT) (envelope-from roam@orbitel.bg) Received: (qmail 70623 invoked by uid 1000); 24 Apr 2001 09:48:58 -0000 Date: Tue, 24 Apr 2001 12:48:57 +0300 From: Peter Pentchev To: Bob Bishop Cc: niek@bergboer.net, freebsd-hackers@FreeBSD.ORG, Mike Silbersack Subject: Re: UFS block size vs. write speed Message-ID: <20010424124857.C22159@ringworld.oblivion.bg> Mail-Followup-To: Bob Bishop , niek@bergboer.net, freebsd-hackers@FreeBSD.ORG, Mike Silbersack References: <20010423134554.A57241@wit379119.student.utwente.nl> <20010424113536.A61988@wit379119.student.utwente.nl> <4.3.2.7.2.20010424103925.00a81ae0@gid.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <4.3.2.7.2.20010424103925.00a81ae0@gid.co.uk>; from rb@gid.co.uk on Tue, Apr 24, 2001 at 10:43:29AM +0100 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, Apr 24, 2001 at 10:43:29AM +0100, Bob Bishop wrote: > Hi, > > At 11:35 24/04/01 +0200, Niek Bergboer wrote: > >[...] > >In fact, I couldn't care less if the allocated blocks contain random > >data (rather than zeros), since I'll be overwriting them immediately. > > You *should* care: the blocks are zeroed for security reasons. But he's only doing a speed test :) And besides, if the 'random data' that's in the blocks is only zeroed for security reasons, there's absolutely no point in zeroing it in the mmap().. If someone removed a file and wanted to make sure no one read his data, the blocks should have been *already* zeroed in the process of removal. (Which, as discussed on several mailing lists lately, cannot really be guaranteed with today's caching/remapping/virtual/whatnot FS's :) G'luck, Peter -- This sentence is false. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message