From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Goran Subject: Re: cannot attach backing device, wipefs does not fix it Date: Wed, 18 Jun 2014 23:01:48 +0700 Message-ID: <1297031660.20140618230148@pvgoran.name> References: Reply-To: Pavel Goran Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from pvgoran2.xen.prgmr.com ([71.19.149.48]:34785 "EHLO v2.pvgoran.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751783AbaFRQCX (ORCPT ); Wed, 18 Jun 2014 12:02:23 -0400 In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: linux-bcache@vger.kernel.org Hello Erik, Wednesday, June 18, 2014, 10:38:55 PM, you wrote: > Hi, ubuntu 14.04, and a 5TB RAID (sdc) partitioned into two 2.5TB partitions > (sdc1 and sdc2) with parted to be used as backing devices, > /dev/sdc2 attaches fine > problem with sdc1: > # make-bcache -B /dev/sdc1 > Device /dev/sdc1 already has a non-bcache superblock, remove it using wipefs > and wipefs -a > # wipefs /dev/sdc1 > wipefs: WARNING: /dev/sdc1: appears to contain 'dos' partition table > # wipefs -a /dev/sdc1 > wipefs: WARNING: /dev/sdc1: appears to contain 'dos' partition table Did you try wipefs -a -f /dev/sdc1 ? If that fails, just erase the first few MB of the device with zeroes: dd if=/dev/zero of=/dev/sdc1 bs=1M count=10 Pavel Goran