From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: no automatic resync after device disconnect then reconnect Date: Thu, 10 Jul 2014 08:58:40 +1000 Message-ID: <20140710085840.78a65722@notabene.brown> References: <883F6A2C-C8F6-4A27-B7BF-2FB98F395592@colorremedies.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/.e=.=bNEl8DVNjuvMiWydPR"; protocol="application/pgp-signature" Return-path: In-Reply-To: <883F6A2C-C8F6-4A27-B7BF-2FB98F395592@colorremedies.com> Sender: linux-raid-owner@vger.kernel.org To: Chris Murphy Cc: "linux-raid@vger.kernel.org List" List-Id: linux-raid.ids --Sig_/.e=.=bNEl8DVNjuvMiWydPR Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 9 Jul 2014 16:44:27 -0600 Chris Murphy wrote: > This is in a VM, no data at risk. >=20 > Two problems: >=20 > 1. I intentionally removed one of two md raid1 member devices, boot degra= ded succeeds, clean power off, reconnect the removed md member device, boot= succeeds but an automatic resync does not occur for the previously disconn= ect md members. Maybe this is expected, I'm not sure, but I'd think a bette= r user experience would be autoresync perhaps with a notification? Do you? Maybe the device was removed from the array because it is faulty. Do you *really* want a faulty device automatically added back into your arr= ay? It is quite possible to set up udev rules and configure mdadm policy to do this. I just don't think it is a sensible default. >=20 > 2. For the raid set with a bitmap, this command succeeds > # mdadm --manage /dev/md126 --re-add /dev/sdb3 Good to know. >=20 > However, for the raid set without bitmap (seems the same otherwise, same = metadata version), it fails: > # mdadm --manage /dev/md127 --re-add /dev/sdb2 > mdadm: --re-add for /dev/sdb2 to /dev/md127 is not possible You need a bitmap to --re-add. Without a bit map, you are just adding an unused device to an array and "--add" is the command to use. If you set up the mdadm policy (in mdadm.conf) suitably then mdadm -I /dev/sdb2 would find the add and --add it for you (I think). NeilBrown > --Sig_/.e=.=bNEl8DVNjuvMiWydPR Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBU73JIDnsnt1WYoG5AQI8xhAAg908v/qhnSigj79QnAM4Z+WJlWlCp4uc HpauED17DcAASESvuQlnRhGjQWFJnoTM6isNPjZGH2WFUJnGu7XSy8DeafM8YM+E Y2iPzlax6IBr6oVimDxdTCNO+CZ8Z+/2TM8uvi7SinuxrYlVUY1AAeYmIH9EIRlw z/d+uwC01cc1LVg0vVC1OCZ+lqRbIHhyRquGwWLiMD3ROY7nRHA+7aYtuHLKyLY2 +yjKrYD5H9F2LSeocPdWtJ4QjybFiJQQVFw3ycYlqC1tfLDnhfKuHRqlabPRP+Ng UMkBSZIouS76ONfZirIgVapJS23o2B+lkFqOTP36TTrAaib7PFbYp+NvGKyNaJk+ H6dj3b0xBYccQIBwMUWlAUmKhZQdKlRuF+H7SC5ZOViqGhORhx0TL6LWRDtvNP8o NW8rWv5M4BDwr4gCRfLDt9NYx0yA6MPJiNenQexGNtipQopQMgwZ+tuzDpy4MvAT zJYl6gdx6I0MjxJm3U1SPdyO/nrTg6CjEZIoJ/YVlS48KoCPtyB4OFHgHjDbsg67 Zr8kVMEhj8ITZatxMFyjm474IBLtpSP+xQuQn3TtBwZkmpZHfhUUseESGEmGX6RT L7xNDUq6tPH09fsKr7Bwheh221kT6Kf8CExcy4J0yDNcTfyHJNL5xyNuF1PUzJmk oSPcpSA0GWw= =X825 -----END PGP SIGNATURE----- --Sig_/.e=.=bNEl8DVNjuvMiWydPR--