From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony DeRobertis Subject: Bug#837964: 95a05b3 broke mdadm --add on my superblock 1.0 array Date: Mon, 19 Sep 2016 12:32:29 -0400 Message-ID: <20160919163229.uccdr6bxiwetqvwo@derobert.net> Reply-To: Anthony DeRobertis , 837964@bugs.debian.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Resent-To: debian-bugs-dist@lists.debian.org Resent-Message-ID: Content-Disposition: inline List-URL: List-Post: List-Help: List-Subscribe: List-Unsubscribe: To: linux-raid@vger.kernel.org Cc: 837964@bugs.debian.org List-Id: linux-raid.ids (please cc me, I'm not subscribed.) mdadm 3.4 can not manage to add a spare to my array, it fails like: # mdadm -a /dev/md/pv0 /dev/sdc3 mdadm: add new device failed for /dev/sdc3 as 8: Invalid argument and the kernel logs: md: sdc3 does not have a valid v1.0 superblock, not importing! md: md_import_device returned -22 This worked in 3.3.4. I performed two git bisects and found that: a) it was broken by 95a05b37e8eb2bc0803b1a0298fce6adc60eff16 b) it is sort-of fixed by 81306e021ebdcc4baef866da82d25c3f0a415d2d (which AFAIK isn't yet released) I say sort of fixed in that it adds it to the array, but spits out some worrying errors (and I have no idea if it'd actually work, e.g., if it'd assemble again): # ./mdadm -a /dev/md/pv0 /dev/sdc3 mdadm: Warning: cluster md only works with superblock 1.2 mdadm: Failed to write metadata to /dev/sdc3 I'm not using (or at least not on purpose!) cluster md, as these are internal SATA drives accessible by only one machine. I wasn't able to reproduce it on a new (small) test array, so it might be something specific to this array. I've reported this bug to Debian, and that bug report contains a lot of system information that I won't repeat here (because it's quite long): https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=837964 that contains mdadm -E output, the mdadm.conf, etc.