From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: Horrible ftruncate performance Date: Wed, 23 Jul 2003 17:39:16 +0400 Message-ID: <3F1E9004.6040800@namesys.com> References: <1058892649.5042.29.camel@tiny.suse.com> <3F1D7DD8.3010806@namesys.com> <200307231425.17476.Dieter.Nuetzel@hamburg.de> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <200307231425.17476.Dieter.Nuetzel@hamburg.de> List-Id: Content-Type: text/plain; charset="iso-8859-1"; format="flowed" To: =?ISO-8859-1?Q?Dieter_N=FCtzel?= Cc: Chris Mason , ReiserFS List Dieter N=FCtzel wrote: >Am Dienstag, 22. Juli 2003 20:09 schrieb Hans Reiser: > =20 > >>Chris Mason wrote: >> =20 >> >>>On Tue, 2003-07-22 at 12:43, Hans Reiser wrote: >>> =20 >>> >>>>The answer to the below is to use reiser4. It uses extents, and two 64 >>>>bit numbers are all that is needed to store the hole. V4 will be ready >>>>for testing in a few days, and will ship for real users at the end of >>>>summer we hope. >>>> >>>>Fixing V3 is the wrong answer: this is one of its design flaws. >>>> =20 >>>> >>>It's important to remember that releasing v4 doesn't automatically >>>convert all existing v3 users to it. This is the kind of thing we >>>should try to fix without making major design changes to v3. It's at >>>least worth talking about, "use v4" can't always be the answer. >>> =20 >>> >>V3 is in feature freeze. Unfortunately, determining what is a feature >>and what is a bug is a process based not just on the user experience, >>but on the structure of the code. The proper fix for this bug is to add >>a feature called extents. This belongs in, and is in, V4. V4 will be >>available very soon. >> =20 >> > >And "coplete" stable from the beginning? --- Come on. > I have been consistently clear in everything I say that V4 will not be=20 as stable as V3 for quite some time. That is because V3 will not=20 significantly change except for bug fixes, whereas V4 is fresh new code. V3 has been dropping in bug reports for quite some time. Unfortunately=20 I have to say we got some this month (direct IO stuff). > > =20 > >>Adding features, like new kinds of items, will disturb the stability of >>V3. V3 needs to be zero defect. It is now in a phase in its lifetime >>where conservatism is appropriate. >> =20 >> > >I'll accept this fix in V3 before I "move" to V4. > >-Dieter > > > > =20 > Most users need for their filesystems to at some point finally get left=20 alone and not disturbed. This is the whole idea behind freeze and=20 release based development. Extents are a nice feature, but they belong in V4 not V3. Effort spent=20 developing extents for V3 is better spent stabilizing V4 which already=20 has them and a lot more. --=20 Hans