From owner-freebsd-current@FreeBSD.ORG Mon Mar 24 05:12:35 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ADD54106566C for ; Mon, 24 Mar 2008 05:12:35 +0000 (UTC) (envelope-from freebsd-current@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id 425298FC26 for ; Mon, 24 Mar 2008 05:12:35 +0000 (UTC) (envelope-from freebsd-current@m.gmane.org) Received: from list by ciao.gmane.org with local (Exim 4.43) id 1Jdez0-00053w-DA for freebsd-current@freebsd.org; Mon, 24 Mar 2008 05:12:30 +0000 Received: from 195.208.174.178 ([195.208.174.178]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Mar 2008 05:12:30 +0000 Received: from vadim_nuclight by 195.208.174.178 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Mar 2008 05:12:30 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-current@freebsd.org From: Vadim Goncharov Date: Mon, 24 Mar 2008 05:12:18 +0000 (UTC) Organization: Nuclear Lightning @ Tomsk, TPU AVTF Hostel Lines: 49 Message-ID: References: <200803181359.m2IDxpdW017638@lurza.secnetix.de> X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 195.208.174.178 X-Comment-To: Oliver Fromme User-Agent: slrn/0.9.8.1 (FreeBSD) Sender: news Subject: Re: RELEASE discs & ISO images (for future) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: vadim_nuclight@mail.ru List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Mar 2008 05:12:35 -0000 Hi Oliver Fromme! On Tue, 18 Mar 2008 14:59:51 +0100 (CET); Oliver Fromme wrote about 'Re: RELEASE discs & ISO images (for future)': >>>>> 224655360 7.0-RELEASE-i386-livefs.iso >>>>> 94493696 7.0-RELEASE-i386-livefs.iso.uzip (16k cluster) >>>>> 110188032 7.0-RELEASE-i386-livefs.iso.uzip (2K cluster) >>>>> >>>>> So the difference is 124 MB for 16K cluster size, and >>>>> 109 MB for 2K cluster size (which is noticably faster >>>>> during access). Actually the space savings will be a >>>>> bit less, because the /boot directory (about 30 MB) >>>>> won't be compressed. So the real gain is probably a >>>>> little less than 100 MB in the 2K case. >>>> >>>> By the way, the maxmum cluster size is 127k or 130048 with uzip, >>>> if you want to maximize the compression ratio. >>> That would make the live FS painfully slow, and it wouldn't >>> make a big difference from the default (16K). >>> It is already noticeably slow with the default cluster size >>> of 16K on my test machine (a 1 GHz VIA C3), so would rather >>> prefer to use 2K cluster size, even though compression will >>> be not quite as good. (2K is the minimum, less than that >>> doesn't make sense for CD9660 media because the physical >>> sector size is 2K.) >> >> How much is slowdown from 2K to 16K ? > It's very noticeable. I haven't done benchmarks, but > you can clearly feel the difference. A find(1) takes > more time. Also man(1) takes longer until the page > comes up. Any kind of random access is slower, unless > all data is already cached. A find(1) on livefs is useless most of time. But man(1) is more valuable, though. > Interestingly there doesn't seem to be a difference > between 2K and 4K, and the difference to 8K is only > very small. But there is a noticeable difference > between 8K and 16K. I don't know why, maybe it's > related to FreeBSD's handling of FS buffers. So > maybe the "optimal" cluster size for an acceptable > performance/compression ratio would be 8K. Agreed. -- WBR, Vadim Goncharov. ICQ#166852181 mailto:vadim_nuclight@mail.ru [Moderator of RU.ANTI-ECOLOGY][FreeBSD][http://antigreen.org][LJ:/nuclight]