From owner-freebsd-stable Sun Sep 30 13:17:18 2001 Delivered-To: freebsd-stable@freebsd.org Received: from pc1-cove4-0-cust214.bir.cable.ntl.com (pc1-cove4-0-cust214.bir.cable.ntl.com [213.105.93.214]) by hub.freebsd.org (Postfix) with ESMTP id 6EA3537B409 for ; Sun, 30 Sep 2001 13:17:14 -0700 (PDT) Received: from ntlworld.com (alpha.private [192.168.0.2]) (authenticated) by pc1-cove4-0-cust214.bir.cable.ntl.com (8.11.6/8.11.6) with ESMTP id f8UKGQ462801 (using TLSv1/SSLv3 with cipher RC4-MD5 (128 bits) verified NO); Sun, 30 Sep 2001 21:16:28 +0100 (BST) (envelope-from ianjhart@ntlworld.com) Message-ID: <3BB77D9A.77B56F56@ntlworld.com> Date: Sun, 30 Sep 2001 21:16:26 +0100 From: ian j hart X-Mailer: Mozilla 4.78 [en] (X11; U; Linux 2.2.12 i386) X-Accept-Language: en MIME-Version: 1.0 To: Ian Dowse Cc: Cy Schubert - ITSD Open Systems Group , Mike Harding , admin@rshb.com.ru, stable@FreeBSD.ORG Subject: Re: dirpref gives massive performance boost References: <200109301852.aa80614@salmon.maths.tcd.ie> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Ian Dowse wrote: > > In message <200109301651.f8UGpFs02421@cwsys.cwsent.com>, Cy Schubert - ITSD Ope > n Systems Group writes: > >In message <20010930162030.10A5B133C1@netcom1.netcom.com>, Mike Harding > >writes: > >> So it sounds like there would be some benefit in tar'ing and untarring > >> /usr/local, /usr/ports, /usr/src, etc. which will be less > >> disruptive... > > > >At work, I don't have the luxury of doing a wholesale conversion as all > >the machines have one disk and most have only one partition. I've been > >toying with the idea of duplicating up /bin for example to /bin.new, > > It is on directory hierarchies such as /usr/ports and /usr/src > where there are a large number of "associated" directories that > the biggest performance improvements are to be made. This is > especially true when the hierarchy takes up only a small proportion > of the whole partition. > > Before the dirpref changes, files were generally allocated physically > close to their parent directory, but directories were spread out > randomly across the filesystem. The dirpref changes make it much > more likely for directories to be located close to their parent > directory too. For /usr/ports, this is a huge win - before these > changes, a port's main directory and its 'files' subdirectory were > located on average a third of the filesystem size away from each > other (I think). Now they are likely to be just a few blocks away, > maybe even waiting in the disk's cache. > > Since these improvements are all about the placing of subdirectories, > there isn't much point in re-creating flat directories such as > /bin, /usr/bin etc. For /usr/local, it might only be worthwhile > re-creating some application directories that have a huge number > of subdirectories. However, a system with a large number of user > home directories might see a big improvement if /home was rebuilt, > because all of a user's files would end up much closer together > on the disk. > > Ian > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-stable" in the body of the message Any effect on vinum? FWIW I have 4 disk raid10 /usr and /var -- ian j hart To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message