From owner-freebsd-fs Tue Jan 25 6:17:57 2000 Delivered-To: freebsd-fs@freebsd.org Received: from abc.aaa-mainstreet.nl (abc.aaa-mainstreet.nl [195.64.77.2]) by hub.freebsd.org (Postfix) with SMTP id A101F15205 for ; Tue, 25 Jan 2000 06:17:49 -0800 (PST) (envelope-from gary@hotlava.com) Received: (qmail 8689 invoked from network); 25 Jan 2000 14:19:51 -0000 Received: from unknown (HELO hotlava.com) (212.186.169.239) by abc.aaa-mainstreet.nl with SMTP; 25 Jan 2000 14:19:51 -0000 Message-ID: <388DB05A.153913B7@hotlava.com> Date: Tue, 25 Jan 2000 15:16:58 +0100 From: Gary Howland Reply-To: gary@hotlava.com Organization: Hotlava Consulting X-Mailer: Mozilla 4.7 [en] (X11; I; FreeBSD 3.4-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: fs@freebsd.org Subject: Re: UDF, userfs References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Steve McIntyre wrote: > > you write: > > > >There are some file systems in the commerical world that "uplink" to > >a user mode daemon that does the actual on-disk work. Without naming > >names, I can think of at least two that actually do this... > > > >They present a pseudo-device which the end-user mounts. This > >pseudo-device catches all the file system requests and "up calls" the > >user mode daemon. The user mode daemon than talks to the real device to > >perform the i/o. I may be able to provide details of the process from > >another Unix system, but not actual code. > > > >This approach seems to handle many o/s'es in that the daemon can be made > >somewhat portable. The pseudo-device, however, is of necessity o/s > >specific. > > You're spot on with the description above - we have jukebox management > software that does exactly this. Our method is portable to AIX, Solaris, > FreeBSD and NT right now, Linux and HP-UX support is coming soon. FYI, CFS (encrypted file system) achieves similar things using a custom NFS daemon, rather than a pseudo device. Gary To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message