From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JSG5k-0003U7-DN for qemu-devel@nongnu.org; Thu, 21 Feb 2008 13:24:20 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JSG5i-0003TC-Q3 for qemu-devel@nongnu.org; Thu, 21 Feb 2008 13:24:19 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JSG5i-0003T5-Gy for qemu-devel@nongnu.org; Thu, 21 Feb 2008 13:24:18 -0500 Received: from mx1.redhat.com ([66.187.233.31]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JSG5i-0008Nj-5h for qemu-devel@nongnu.org; Thu, 21 Feb 2008 13:24:18 -0500 Date: Thu, 21 Feb 2008 18:24:14 +0000 From: "Daniel P. Berrange" Subject: Re: [Qemu-devel] [PATCH] bdrv_flush error handling Message-ID: <20080221182414.GO15883@redhat.com> References: <20080220160457.GD14209@redhat.com> <20080221121922.35DF1.4126.imail@eastrmwml17.mgt.cox.net> <20080221172410.GN15883@redhat.com> <20080221172823.GD14090@volumehost.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080221172823.GD14090@volumehost.com> Reply-To: "Daniel P. Berrange" , qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: risc@volumehost.com Cc: qemu-devel@nongnu.org On Thu, Feb 21, 2008 at 11:28:23AM -0600, risc@volumehost.com wrote: > On Thu, Feb 21, 2008 at 05:24:10PM +0000, Daniel P. Berrange wrote: > > On Thu, Feb 21, 2008 at 12:19:22PM -0500, Ben Taylor wrote: > > > > > Also, in block-raw-posix.c, raw_pwrite et al seem to return -1 on > > > > > error (the return value from write) whereas the other block read/write > > > > > methods return errno values. This is a mistake, surely ? -1 would be > > > > > -EPERM. If any of the callers did anything with these return values > > > > > you'd get incorrect error indications. > > > > > > > > > > > > > > > Finally, it would perhaps be best if the block device emulators wrote > > > > > to the qemu console to complain if they give write errors. Otherwise > > > > > the errno value and other important information will be lost, which > > > > > makes debugging hard. > > > > > > > > If by 'qemu console' you mean stderr, then fine, but please don't > > > > spew log messages to the monitor console, because that'll make it > > > > very hard to interact with reliably from management tools. > > > > > > Would it make sense to have a log messages screen associated with > > > the monitor (like Ctrl-Alt-7) to deal with those sorts of things? > > > > Why invent a new special QEMU log screen, when stderr works just fine. If an > > app wants to capture log messages they just capture stderr and persist it. > > We already capture stderr for exactly this reason in libvirt when managing > > QEMU instances. > > Please excuse my intrusion in this thread, but I'm a user of the new > ncurses user interface. when ssh'd in, running qemu, I don't believe > having messages pop out of stderr and over the current screen contents is > the appropriate behavior, as it sounds to me like it would cause redraw > defects in the normal text console (via ncurses) So just redirect stderr to a logfile, or /dev/null, etc, etc Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|