From owner-freebsd-questions Sat Aug 28 19:58: 7 1999 Delivered-To: freebsd-questions@freebsd.org Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by hub.freebsd.org (Postfix) with ESMTP id 02E3F15142 for ; Sat, 28 Aug 1999 19:58:01 -0700 (PDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.9.3/8.9.3) id VAA75795; Sat, 28 Aug 1999 21:57:54 -0500 (CDT) (envelope-from dan) Date: Sat, 28 Aug 1999 21:57:54 -0500 From: Dan Nelson To: "Ronald F. Guilmette" Cc: questions@FreeBSD.ORG Subject: Re: Disk allocation chunk size (?) Message-ID: <19990828215754.A74721@dan.emsphone.com> References: <20038.935892300@monkeys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.7i In-Reply-To: <20038.935892300@monkeys.com> X-OS: FreeBSD 4.0-CURRENT Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In the last episode (Aug 28), Ronald F. Guilmette said: > Assume that I'm using FreeBSD 2.2.8 on an x86, straight out of the > box. Now assume that I create, on disk, one million files, each one > byte in length. Ignoring directory and inode overhead, how much > space will actually be consumed on disk? > > What I'm asking is: What is the actually allocation chunk size used > by the ufs file system these days. > > Once upon a time, it was 1 KB, then 2KB, then 4KB, and I have no idea > what it is nowadays. ffs has two allocation sizes. The block size is 8KB. The minimum allocatable unit on the filesytem is the "frag" size, however, which is 1K by default. Files smaller than the block size may use one or more frags instead. See /usr/share/doc/smm/05.fastfs/paper.ascii.gz for more details. -- Dan Nelson dnelson@emsphone.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message