From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Out of sync mirrors Date: Thu, 24 Jul 2008 18:37:55 -0400 Message-ID: <48890443.5000003@tmr.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Ana Paula Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Ana Paula wrote: > Hi, > I am using linux 2.6.8 for my research on raid systems. > > I need to have the disks of an array out of sync for a while. > I want to be able to stop a disk request queue (blk_stop_queue) and > start it sometime later. Meanwhile its mirrors should be serving r/w > as if this mirror was up. > Whenever the stopped mirror comes back it will serve all the requests > already sent to it. > > I am queueing up the requests sent to all others while my mirror queue > is stopped. > > The problem is that the other mirrors stop serving as well. Even if I > don't stop the queue, only delay its request a little bit, still the > others also slow down. > > Question: how do I get raid to allow mirrors to be out of sync? > > Obviously, I am missing something out in the code. > > Any clues? > Take a look at "write-mostly" and see if creative use of it will assist. I suspect you're doing something which needs a bitmap, as well. -- Bill Davidsen "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark