From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: Silly question, defrag Date: Thu, 04 Apr 2002 00:44:15 +0400 Message-ID: <3CAB699F.8000706@namesys.com> References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit list-help: list-unsubscribe: list-post: List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Richard Thornton Cc: Ross Vandegrift , Matthew Johnson , reiserfs-list@namesys.com Richard Thornton wrote: >Why doesn't linux use UFS? I can't understand this. > >Richard > > >On Wed, 3 Apr 2002, Ross Vandegrift wrote: > >>On Wed, Apr 03, 2002 at 08:08:21AM -0800, Matthew Johnson wrote: >> >>>On Wednesday 03 April 2002 00:21, Joe Cooper wrote: >>> >>>>"Don't" >>>> >>>Well I don't, but when newbies who are used to computing on win32 systems >>>hear that they may not just accept the word don't. Actually its hard to find >>>the reasons exactly why one does not defrag. >>> >>Depending on the elevator algorithms in Linux (sorry, I'm not very >>familiar with them), performance can actually be *increased* by >>some bit of fragmentation. If the data is spread out over the disk, >>I've heard it allows some elevator algorithms to improve their queuing >>stategies. I'm pretty sure this is the case on Novell Netware. >> >>Unfortunately I don't have enough technical knowledge about elevator >>algorithms to really know if it helps or hurts us. However, I do know >>that back in the days when I was just getting into Linux stuff >>(around 2.0.0-ish era), it was generally said that ext2 driver did basic >>defrag on write and it limited fragmentation to pathological filesystem >>usage. >> >>Again, not sure that this is still the case. >> >>Ross Vandegrift >>ross@willow.seitz.com >> > > > UFS is slower than ext2 by a lot. Hans