From owner-freebsd-geom@freebsd.org Mon Dec 9 11:22:39 2019 Return-Path: Delivered-To: freebsd-geom@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 1878C1D3FFA for ; Mon, 9 Dec 2019 11:22:39 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 47Wglf6zn2z4W4J for ; Mon, 9 Dec 2019 11:22:38 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id EF7CF1D3FF8; Mon, 9 Dec 2019 11:22:38 +0000 (UTC) Delivered-To: geom@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id EE3491D3FF7 for ; Mon, 9 Dec 2019 11:22:38 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47Wglf60slz4W4H for ; Mon, 9 Dec 2019 11:22:38 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id C980719DF4 for ; Mon, 9 Dec 2019 11:22:38 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id xB9BMcxx014008 for ; Mon, 9 Dec 2019 11:22:38 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id xB9BMc0w013977 for geom@FreeBSD.org; Mon, 9 Dec 2019 11:22:38 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: geom@FreeBSD.org Subject: [Bug 242341] GEOM / GEOM_PART: silent discard MBR modification Date: Mon, 09 Dec 2019 11:22:38 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 12.1-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: ae@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: geom@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Dec 2019 11:22:39 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D242341 --- Comment #5 from Andrey V. Elsukov --- (In reply to Tomasz "CeDeROM" CEDRO from comment #3) > 1. I would like to clarify why I was unable to write to MBR (first 512 by= tes) of the da1 while there was no problem with writhing to the rest of the= disk? How did you know that? Did you compare the first 512 bytes on both disks af= ter copying? > 2. GEOM_PART: integrity check failed (da1, MBR) <- could that block / dis= card writes to MBR silently? This usually means that parition table's metadata is wrong. If it is wrong,= and kern.geom.part.check_integrity is set, then GEOM_PART just ignores the partition table. > 3. Why `dd if=3D/dev/da0 of=3D/dev/da1` did copy all disk except the MBR? How did you know that? Did you compare the first 512 bytes on both disks af= ter copying? I assume you have disks with different size and GEOM_PART just rej= ects MBR on the copied disk, because its integrity check has failed.=20 > 4. Why I was unable to write to MBR from a file but it was possible to wr= ite that data from a file over md0? Again, how did you know that? --=20 You are receiving this mail because: You are the assignee for the bug.=