From owner-freebsd-hackers Tue Oct 1 11:16:48 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id LAA07107 for hackers-outgoing; Tue, 1 Oct 1996 11:16:48 -0700 (PDT) Received: from lestat.nas.nasa.gov (lestat.nas.nasa.gov [129.99.50.29]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id LAA07101 for ; Tue, 1 Oct 1996 11:16:46 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by lestat.nas.nasa.gov (8.7.5/8.6.12) with SMTP id LAA02439; Tue, 1 Oct 1996 11:06:18 -0700 (PDT) Message-Id: <199610011806.LAA02439@lestat.nas.nasa.gov> X-Authentication-Warning: lestat.nas.nasa.gov: Host localhost [127.0.0.1] didn't use HELO protocol To: "Justin T. Gibbs" Cc: Poul-Henning Kamp , James Graham , "Kevin P. Neal" , hackers@freebsd.org, tech-kern@netbsd.org Subject: Re: VPS mailing list, BSD interest? Reply-To: Jason Thorpe From: Jason Thorpe Date: Tue, 01 Oct 1996 11:06:17 -0700 Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Tue, 01 Oct 1996 09:53:02 -0700 "Justin T. Gibbs" wrote: > Actually, I don't think it is. CCD should be relying on information stored > in a private area of the disk to determine what stripe sets what partitions > belong to, etc. This is how all of the industrial strength filesystem VM > systems work. When you open the partition, you see it has a CCD block > on it, and then pass it on to CCD informing it of the dev that the block > came from. The upside to this is that you can re-arange your disks (even > put them on different controllers) and the system still finds your array > and makes it work. Having my root FS on a RAID 5 device makes it > more robust than having it on a single disk. This is more than enough > justification for allowing you to do this. Just where do you propose to keep this information? (Hint: it's going to be machine-dependent.) When you say "open the partition", which partition are you opening? (Hint: if you're opening /dev/sd0a, then you have to put all kinds of crap to find the "ccd block" in the SCSI disk driver, and the IDE disk driver, and the Xylogics disk drivers, and...) How does the way the ccd is configured not allow you to move your disks around (to different controllers, etc.)? (Hint: it doesn't.) Jason R. Thorpe thorpej@nas.nasa.gov NASA Ames Research Center Home: 408.866.1912 NAS: M/S 258-6 Work: 415.604.0935 Moffett Field, CA 94035 Pager: 415.428.6939