From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1Z9Gyu-0005xN-PM for mharc-grub-devel@gnu.org; Sun, 28 Jun 2015 14:07:04 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54236) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9Gys-0005uY-GJ for grub-devel@gnu.org; Sun, 28 Jun 2015 14:07:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z9Gyn-0002ao-Hi for grub-devel@gnu.org; Sun, 28 Jun 2015 14:07:02 -0400 Received: from mail-la0-x22c.google.com ([2a00:1450:4010:c03::22c]:32908) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9Gyn-0002aW-A1 for grub-devel@gnu.org; Sun, 28 Jun 2015 14:06:57 -0400 Received: by laar3 with SMTP id r3so40484582laa.0 for ; Sun, 28 Jun 2015 11:06:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:subject:message-id:mime-version:content-type :content-transfer-encoding; bh=GH5P3GBrrZguDeGC/y8owkFD3cHS2oUP4G8p9igqTpY=; b=EjjGY0ectOLxJ/EM7keXy++z/y/HeJzu/7QWgfeS4DUCrJAMIlTsgWVs+A0FEOW0G0 uStYE12lNEmOF1u8zUaSdwgQN6o+VeE501NuGK5NIoS2GcARn+CdsSKdvTZKn6K5QbLI h+v01pBJ3EQksAC+1GtAMi5vp1caGk70ZozHfGTx/jx40TpCW7Kd6ZkxyaEVREO8gtdr 1W8U8UySxytZQWKxqPOPiA9tpjzXXoaOiTAK1gaaecR48InsYYSOxB5r4tmrv1yZpNmJ lI8Mn5fxwDOpN7vLy8SCiFPgLiAPREFy5sZ2ZESuwuCDwLKJPzLsi4Ahs7DopBMf4Arm 9S3A== X-Received: by 10.112.199.133 with SMTP id jk5mr10890854lbc.32.1435514816565; Sun, 28 Jun 2015 11:06:56 -0700 (PDT) Received: from opensuse.site (ppp91-76-14-38.pppoe.mtu-net.ru. [91.76.14.38]) by mx.google.com with ESMTPSA id w9sm10003680laj.21.2015.06.28.11.06.55 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 28 Jun 2015 11:06:55 -0700 (PDT) Date: Sun, 28 Jun 2015 21:06:55 +0300 From: Andrei Borzenkov To: Subject: [RFD] diskfilter stale RAID member detection vs. lazy scanning Message-ID: <20150628210655.6dfdbd9a@opensuse.site> X-Mailer: Claws Mail 3.11.0 (GTK+ 2.24.28; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a00:1450:4010:c03::22c 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: Sun, 28 Jun 2015 18:07:03 -0000 I was looking at implementing detection of outdated RAID members. Unfortunately it appears to be fundamentally incompatible with lazy scanning as implemented currently by GRUB. We simply cannot stop scanning for other copies of metadata once "enough" was seen. Because any other disk may contain more actual copy which invalidates everything seen up to this point. So basically either we officially admit that GRUB is not able to detect stale members or we drop lazy scanning. Comments, ideas?