From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Rabbitson Subject: Re: mismatch_cnt questions - how about raid10? Date: Tue, 06 Mar 2007 11:04:33 +0100 Message-ID: <45ED3CB1.8070003@rabbit.us> References: <17898.45673.573800.56474@notabene.brown> <17899.17901.429001.702653@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <17899.17901.429001.702653@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > When we write to a raid1, the data is DMAed from memory out to each > device independently, so if the memory changes between the two (or > more) DMA operations, you will get inconsistency between the devices. Does this apply to raid 10 devices too? And in case of LVM if swap is on top of a LV which is a part of a VG which has a single PV as the raid array - will this happen as well? Or will the LVM layer take the data once and distribute exact copies of it to the PVs (in this case just the raid) effectively giving the raid array invariable data?