From owner-freebsd-questions Thu Feb 12 07:51:33 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA12382 for questions-outgoing; Thu, 12 Feb 1998 07:51:33 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from gwdu60.gwdg.de (gwdu60.gwdg.de [134.76.10.60]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA12362 for ; Thu, 12 Feb 1998 07:51:15 -0800 (PST) (envelope-from kheuer@gwdu60.gwdg.de) Received: from localhost (kheuer@localhost) by gwdu60.gwdg.de (8.8.5/8.8.5) with SMTP id QAA24864; Thu, 12 Feb 1998 16:50:50 +0100 (CET) Date: Thu, 12 Feb 1998 16:50:50 +0100 (CET) From: Konrad Heuer To: Vincent Defert cc: freebsd-questions@FreeBSD.ORG Subject: Re: FreeBSD vs Linux In-Reply-To: <34E1DAF1.4A47@trace.fr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 11 Feb 1998, Vincent Defert wrote: > I am using an old version of Linux and I consider upgrading. > FreeBSD seems to have a very positive image, but the same is > true of Linux. > > Could you please explain the main differences between them, > and why people who tested both systems chose FreeBSD rather > than Linux? During the last months I spent a lot of time in comparing FreeBSD (2.2.2-RELEASE) to Linux (2.0.30) on the same machine (P90) embedded in a heterogenous environment (DECalpha systems running Digital UNIX, SPARC systems running Solaris etc.). Major technical differences I found by a couple of performance measurements and code studies are: 1. The Linux scheduler which is very different from other UNIX schedulers (and thus the FreeBSD scheduler) behaves very poor when the system is heavily loaded (no fair scheduling!). 2. The Linux NFS implementation doesn't compare to the FreeBSD implementation. It's neither Version 3 as in FreeBSD nor does it support write-behind by the nfsiod daemons. So for NFS clients which need write access Linux is a bad choice (only about 1/3 of the FreeBSD performance). 3. Since the Linux 2nd Extended File Systems by default also buffers inode and comparable data it's faster in operations like unpacking tar files. With some risk one can mount a FreeBSD Fast File System with an async option but then the dirty buffers containing critical data will be flushed only in 30 second intervals. Linux runs a special bdflush daemon with a 5 second interval for critical data which is more reliable. On the other hand I found the sequential writes and (much more important) reads of larger files are about 30%..50% faster with FreeBSD and the FFS. Last, non-technical point: For people like me who are accustomed to UNIX for years FreeBSD is very pleasing since it is in fact *UNIX* although it doesn't wear the trademark. Linux is Linux and no UNIX - it's a reimplementation with a lot of more or less perceptible small differences. Konrad Heuer, GWDG, Goettingen, Germany (kheuer@gwdu60.gwdg.de) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe questions" in the body of the message