From owner-freebsd-bugs@freebsd.org Tue Mar 13 23:07:24 2018 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 70CADF58AFD for ; Tue, 13 Mar 2018 23:07:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0EAB97B571 for ; Tue, 13 Mar 2018 23:07:24 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 5162426BCA for ; Tue, 13 Mar 2018 23:07:23 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w2DN7N3R086552 for ; Tue, 13 Mar 2018 23:07:23 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w2DN7NRE086551 for freebsd-bugs@FreeBSD.org; Tue, 13 Mar 2018 23:07:23 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: freebsd-bugs@FreeBSD.org Subject: [Bug 226583] FreeBSD VM on Hyper-V/Azure can't properly detected SCSI disk da2 Date: Tue, 13 Mar 2018 23:07:23 +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: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: decui@microsoft.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@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-bugs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Mar 2018 23:07:24 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D226583 --- Comment #1 from Dexuan Cui --- When the issue happens, the Azure host (in the VM, "dmesg |grep "Hyper-V Version" shows: "Hyper-V Version: 10.0.14393 [SP0]) reports da2 as a SPC-2 device. I tried to reproduce the bug on local Hyper-V hosts (which always report da2 as a SPC-3 device), but I couldn't repro it. So far, I can only reproduce the bug with some specific VM sizes, e.g. Stan= dard D4 v2 (8 vcpus, 28 GB memory) ) in West Central US region. Note: some people also reported some other VM sizes can also reproduce the bug. It looks all = the affected VM sizes use HDD-backed disks. If we create a VM with SSD-backed disks, the bug can't repro. And, with a HDD-backed disk, if we avoid attach= ing the disk to LUN0, it looks the bug can't repro either. So, two possible mitigation solutions are: a) use a VM size that supports SSD-backed disks; b) attach any extra data disk to a LUN whose number is not zero. --=20 You are receiving this mail because: You are the assignee for the bug.=