From mboxrd@z Thu Jan 1 00:00:00 1970 From: ross@jose.lug.udel.edu (Ross Vandegrift) Subject: Re: raid1 mysteriously switching to read-only Date: Sun, 11 Dec 2005 12:13:50 -0500 Message-ID: <20051211171350.GA18610@jose.lug.udel.edu> References: <1051127234104.14937@suse.de> <17306.31969.240202.416327@cse.unsw.edu.au> <17306.35737.880103.939683@cse.unsw.edu.au> <17306.50617.458648.8740@cse.unsw.edu.au> <439C344F.9020408@ucolick.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Yanggun Cc: Patrik Jonsson , Neil Brown , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sun, Dec 11, 2005 at 11:29:23PM +0900, Yanggun wrote: > I did not find involved part with this in the document. > > I am sorry, inform it is what section. Basically, the md driver acts like another hard disk. So a regular setup looks like this: --------------------------------- | | | Applications (ls, cat) | | | --------------------------------- | v --------------------------------- | | | Filesystem (ext3) | | | --------------------------------- | v --------------------------------- | | | Block layer (sda1/sdb1) | | | --------------------------------- and a software RAID setup looks like this: --------------------------------- | | | Applications (ls, cat) | | | --------------------------------- | v --------------------------------- | | | Filesystem (ext3) | | | --------------------------------- | v --------------------------------- | | | Block layer (md0) | | | --------------------------------- | v --------------------------------- | | | Block Layer (sda1/sdb1) | | | --------------------------------- The format of sda1/sdb1 is the RAID data that the md driver writes to them. It form a complete layer of abstraction between your applications and the actual devices you are storing data on. -- Ross Vandegrift ross@lug.udel.edu "The good Christian should beware of mathematicians, and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of Hell." --St. Augustine, De Genesi ad Litteram, Book II, xviii, 37