From owner-freebsd-fs Mon Oct 12 19:14:31 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA05880 for freebsd-fs-outgoing; Mon, 12 Oct 1998 19:14:31 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA05871 for ; Mon, 12 Oct 1998 19:14:27 -0700 (PDT) (envelope-from grog@freebie.lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.9.1/8.9.0) with ESMTP id LAA21309; Tue, 13 Oct 1998 11:44:11 +0930 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.9.1/8.9.0) id LAA19951; Tue, 13 Oct 1998 11:44:11 +0930 (CST) Message-ID: <19981013114410.A21983@freebie.lemis.com> Date: Tue, 13 Oct 1998 11:44:10 +0930 From: Greg Lehey To: Terry Lambert , francisco@natserv.com Cc: freebsd-fs@FreeBSD.ORG Subject: Re: Optimizing space utilization References: <199810110304.XAA22392@federation.addy.com> <199810122018.NAA21730@usr07.primenet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.91.1i In-Reply-To: <199810122018.NAA21730@usr07.primenet.com>; from Terry Lambert on Mon, Oct 12, 1998 at 08:18:53PM +0000 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Monday, 12 October 1998 at 20:18:53 +0000, Terry Lambert wrote: >>>> On a 1 Gig partition by using 1/4 the number of inodes (sent -i 16384 >>>> to newfs) I was able to save a little over 30MB. A 3% saving. :-) >>>> I was still left with over 64K inodes, which I doubt I will use. >> >>> Interesting. At 262 bytes per inode, I'd only expect a saving of >>> about 12 MB. > > Uh, what are you smoking? Cooked inodes. > An inode is 128 bytes, exactly, including reserve space. Oops. The in-core inode is 262 bytes, which isn't particularly relevant to the disk. Where should I have been looking (i.e. which file?). > Are you perhaps counting the mandatory 24 byte overhead on a directory > entry, and assuming a 110 byte file name? If so, you should be > aware that flexname allocations must round to 4 byte boundaries, > so you are off by 2 (108 and 112 are evenly divisible by 4). No. Here's a test program: #define MAXQUOTAS 2 #include "/T/vinum/vinumhdr.h" #include main () { printf ("inode size is %d\n", sizeof (struct inode)); } The MAXQUOTAS is because I didn't want a whole slew of knotted header files. vinumhdr is gratuitous, but save more knotted header files. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message