From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1Xqvle-000640-PS for mharc-grub-devel@gnu.org; Tue, 18 Nov 2014 22:17:18 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51141) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XqvlT-00062b-3w for grub-devel@gnu.org; Tue, 18 Nov 2014 22:17:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XqvlK-00008i-47 for grub-devel@gnu.org; Tue, 18 Nov 2014 22:17:07 -0500 Received: from mail-lb0-x22a.google.com ([2a00:1450:4010:c04::22a]:48415) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XqvlJ-00008P-OX for grub-devel@gnu.org; Tue, 18 Nov 2014 22:16:58 -0500 Received: by mail-lb0-f170.google.com with SMTP id w7so10025594lbi.15 for ; Tue, 18 Nov 2014 19:16:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; bh=7aRPIxEudON/QXOjooHqUaRGwaQEX73wBb/XEinZ5Oc=; b=s2RPwUeaIQcp99EREcGQLrIf0uShZJKII+LLiAvcoyd6ogbejIVuzcUhL8L4bBObrM SK399Ab5zwVw/JS52c5DGLsUwDJNK8HeSb+mCoEBc+WIkeBr7BiV2DOa905w6sxBP+p7 bD+zmuUg6r5gsyk6T9W3o0Xl2CmPeV15yFYLQV2Trdn7U2NboLmXweai4KFprkbC1M2F lb0pOLhqPlzGy2VH0DfMfpqDi8Zr/SUvOkkYFcdZHmMWLjxZo2F1Gwv+PI+IKB0SrumJ ipl8ugIbQbB0i0s0SpE2ZF0xK8ftkGGNhPxMtCDUn2i0+yuD3meI41d1SKduGprMKety RYjg== X-Received: by 10.112.172.97 with SMTP id bb1mr2875680lbc.38.1416367016577; Tue, 18 Nov 2014 19:16:56 -0800 (PST) Received: from opensuse.site (ppp91-76-139-38.pppoe.mtu-net.ru. [91.76.139.38]) by mx.google.com with ESMTPSA id ed8sm108019lbb.41.2014.11.18.19.16.55 for (version=SSLv3 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 18 Nov 2014 19:16:55 -0800 (PST) Date: Wed, 19 Nov 2014 06:16:54 +0300 From: Andrei Borzenkov To: Venkata Subbarao Subject: Re: Switching to another boot device on failure Message-ID: <20141119061654.3de675c8@opensuse.site> In-Reply-To: References: X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.24; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a00:1450:4010:c04::22a Cc: grub-devel@gnu.org X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Nov 2014 03:17:16 -0000 =D0=92 Tue, 18 Nov 2014 10:51:00 +0000 (UTC) Venkata Subbarao =D0=BF=D0=B8=D1=88=D0=B5=D1= =82: > Hi All, >=20 > I am working on a task on XUbuntu OS in which due to any reason if booting > fails I would like to switch to another boot device by zeroing the MBR of > current boot disk. Is this possible ? >=20 > For example instead of showing following prompt, I would like to zero out > the MBR so that the BIOS can select next boot device upon reset. >=20 > error: no such partition > grub rescue> >=20 grub supports only very limited and controlled ways to write to device/file. Doing something like this in unattended manner is probably way too dangerous. What would be possible is to optionally exit grub (after timeout) in this case; then BIOS should proceed to next boot device.