From owner-freebsd-hackers Mon Mar 2 15:23:50 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA13656 for freebsd-hackers-outgoing; Mon, 2 Mar 1998 15:23:50 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from smtp03.primenet.com (smtp03.primenet.com [206.165.6.133]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA13558 for ; Mon, 2 Mar 1998 15:23:29 -0800 (PST) (envelope-from tlambert@usr09.primenet.com) Received: (from daemon@localhost) by smtp03.primenet.com (8.8.8/8.8.8) id QAA18561; Mon, 2 Mar 1998 16:23:25 -0700 (MST) Received: from usr09.primenet.com(206.165.6.209) via SMTP by smtp03.primenet.com, id smtpd018540; Mon Mar 2 16:23:24 1998 Received: (from tlambert@localhost) by usr09.primenet.com (8.8.5/8.8.5) id QAA24805; Mon, 2 Mar 1998 16:23:15 -0700 (MST) From: Terry Lambert Message-Id: <199803022323.QAA24805@usr09.primenet.com> Subject: Re: SCSI Bus redundancy... To: sbabkin@dcn.att.com Date: Mon, 2 Mar 1998 23:23:14 +0000 (GMT) Cc: tlambert@primenet.com, shimon@simon-shapiro.org, wilko@yedi.iaf.nl, grog@lemis.com, jdn@acp.qiv.com, blkirk@float.eli.net, hackers@FreeBSD.ORG In-Reply-To: from "sbabkin@dcn.att.com" at Mar 2, 98 02:23:50 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > You would have to remember to grab the blocks to be relocated with > > the same O(n) randomness as their allocation. 8-). > > Huh ? Probably I've missed something about RAIDs. I've thought > that, for example, RAID block 0 consists of blocks 0 of all > the physical disks. And so on. And I've thought that RAID itself > does not allocate any blocks, the upper level like filesystem or > volume manager does it, RAID just makes chechsuming. Am I wrong again ? If I allocate N stripes on M devices, I have N/M stripes per device. If I add a device, I do not automagically end up with N/(M+1) stripes per device. I have to move some stripes around. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message