From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754846Ab2GQIy7 (ORCPT ); Tue, 17 Jul 2012 04:54:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52645 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752989Ab2GQIy5 (ORCPT ); Tue, 17 Jul 2012 04:54:57 -0400 Message-ID: <5005285E.8060706@redhat.com> Date: Tue, 17 Jul 2012 10:54:54 +0200 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: James Bottomley CC: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Subject: Re: [PATCH] sd: do not set changed flag on all unit attention conditions References: <1342454772-9018-1-git-send-email-pbonzini@redhat.com> <1342455503.3176.42.camel@dabdike.int.hansenpartnership.com> <50044D56.6000400@redhat.com> <1342511100.3039.9.camel@dabdike.int.hansenpartnership.com> <50052390.7030908@redhat.com> <1342514444.3039.23.camel@dabdike.int.hansenpartnership.com> In-Reply-To: <1342514444.3039.23.camel@dabdike.int.hansenpartnership.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 17/07/2012 10:40, James Bottomley ha scritto: >> > >> > It's not specific to virtio-scsi, in fact I expect that virtio-scsi will >> > be almost always used with non-removable disks. >> > >> > However, QEMU's SCSI target is not used just for virtio-scsi (for >> > example it can be used for USB storage), and it lets you mark a disk as >> > removable---why? because there exists real hardware that presents itself >> > as an SBC removable disk. The only thing that is specific to >> > virtualization, is support for online resizing (which generates a unit >> > attention condition CAPACITY DATA HAS CHANGED). > So what's the problem? If you're doing pass through of a physical disk, > we pick up removable from its inquiry string ... a physical removable > device doesn't get resized. If you have a virtual disk you want to > resize, you don't set the removable flag in the inquiry data. In practice people will do what you said, and it's not a problem. However, there's nothing that prevents you from running qemu with a removable SCSI disk, and then resizing it. I would like this to work, because SBC allows it and there's no reason why it shouldn't. Paolo