From owner-freebsd-hackers Wed Nov 3 14:54:59 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from catarina.usc.edu (catarina.usc.edu [128.125.51.47]) by hub.freebsd.org (Postfix) with SMTP id F39F815517; Wed, 3 Nov 1999 14:54:42 -0800 (PST) (envelope-from xuanchen@catarina.usc.edu) Received: from ipanema.usc.edu (ipanema.usc.edu [128.125.52.3]) by catarina.usc.edu (8.6.10/8.6.9) with ESMTP id OAA20748; Wed, 3 Nov 1999 14:53:50 -0800 Received: from localhost (xuanchen@localhost) by ipanema.usc.edu (8.9.3/8.6.9) with ESMTP id OAA01486; Wed, 3 Nov 1999 14:53:34 -0800 (PST) X-Authentication-Warning: ipanema.usc.edu: xuanchen owned process doing -bs Date: Wed, 3 Nov 1999 14:53:34 -0800 (PST) From: Xuan Chen To: freebsd-hardware@FreeBSD.ORG Cc: freebsd-hackers@FreeBSD.ORG Subject: Suggestion for servers running FreeBSD In-Reply-To: <199911032013.PAA11451@lor.watermarkgroup.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hello, We are thinking of getting new servers for our lab, and run FreeBSD on it. What kind of servers should we get, which will not cause too much headache, ie. can work reliablely? Any suggestion will be greatly appreciated! Cheers, -chen On Wed, 3 Nov 1999, Luoqi Chen wrote: > > :Thanks. It seems to me that for a filesystem, a block (or a fragment) is > > :the unit of I/O. Even if a single byte is modified, an entire block > > :probably consisting of multiple sectors must be written back to the disk. > > :As you said, there is no differnce whether we write this block one sector > > :at a time or in a single transfer. If so, I wonder whether the atomicity > > :of a sector I/O required by a directory file is necessary any more. > > : > > :-Zhihui > > > > The directory blocking is there for a different reason. Atomicy does not > > have much to do with it though perhaps it did at some point in the past. > > > I think atomicity is still the reason. The basic block size of a directory > is still a 512-byte sector, and chances are we might write directory blocks > one sector at a time (4k/512 formatted fs), so we have to guarantee directory > entries don't cross the 512-byte sector boundary. On a 8k/1k fs, you probably > could get away with crossing the odd 512-byte sector boundary though. > > -lq > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message