From owner-freebsd-hackers Wed Apr 15 10:42:33 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id KAA24597 for freebsd-hackers-outgoing; Wed, 15 Apr 1998 10:42:33 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from shark.nas.nasa.gov (shark.nas.nasa.gov [129.99.34.41]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id RAA23952 for ; Wed, 15 Apr 1998 17:40:57 GMT (envelope-from edavis@shark.nas.nasa.gov) Received: from shark.nas.nasa.gov (edavis@localhost) by shark.nas.nasa.gov (8.8.7/NAS8.8.7) with ESMTP id KAA26082; Wed, 15 Apr 1998 10:40:34 -0700 (PDT) Message-Id: <199804151740.KAA26082@shark.nas.nasa.gov> X-Mailer: exmh version 2.0.2 2/24/98 To: sfarrell+lists@farrell.org cc: Dan Nelson , "Matthew N. Dodd" , Eivind Eklund , edavis@shark.nas.nasa.gov, freebsd-hackers@FreeBSD.ORG Subject: Re: how to add new system calls... In-reply-to: sfarrell+lists's message of 15 Apr 1998 12:07:36 -0500.<87hg3vko87.fsf@phaedrus.uchicago.edu> Date: Wed, 15 Apr 1998 10:40:33 -0700 From: "Eric A. Davis" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 15 Apr 1998 12:07:36 -0500 sfarrell+lists@farrell.org wrote >Dan Nelson writes: > >> In the last episode (Apr 15), Matthew N. Dodd said: >> > On Wed, 15 Apr 1998, Eivind Eklund wrote: >> > > YES! I've been missing this since I left my Amiga 5 years ago! >> > > >> > > Does the above imply watching for changes in directories, too? Ie, >> > > file added to directory, notification sent... >> > > >> > > What level of notification? Do you get information saying 'file so >> > > changed atime to XXX'/'file XXX added to directory', or just a flag >> > > saying 'event so happened on descriptor so'? >> > >> > Mmm... tripwired >> >> Sort of like tripwire, but in real time. The Amiga has a feature where >> you could monitor a file or directory for changes. Imagine cron >> getting a signal when /var/cron/tabs changes. Or any other daemon that >> has a config file. There's a description of the function (but not the >> assosicated structures unfortunately) at > >Also applicable, perhaps, to GUI items like file managers so they do >not need to poll the directory. > Let me tell you what we are doing here at the NAS. We have approx 200 users publishing web pages. All web pages are located on a central 'build' box were the users do their editing. This 'build' box is a powerful SGI system running IRIX 6.2. The IRIX kernel has a facility called imon & fam that allows real time monitoring of the filesystem. I wrote an application that monitors _all_ the web files. There are over xxxx files and directories that are being monitored. This has worked out _extremely_ well for us. Any time a change occurs within these filesystems my application immediately notices it and copies/updates/makes the changes on our actual server located in a DMZ. This is great because using this paradigm we can also manage the ownership and permissions of the files on our servers. For the updates between our 'build' box and our servers we have written a fast transfer client/server app that uses digital certificates and SSL. I realize this description isn't for this kernel list but I just wanted let you all know the usefulness of such a kernel facility. Besides, don't we all look for alternatives to NFS. ;-) - e -- Eric Allen Davis Network Engineer edavis@nas.nasa.gov NASA Ames Research Center Voice: (415)604-2543 NAS Systems Division Pager: (415)428-6931 http://www.nas.nasa.gov/~edavis To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message