From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:55183) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QXa4I-00088K-T4 for qemu-devel@nongnu.org; Fri, 17 Jun 2011 10:30:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QXa4F-0007aU-Qs for qemu-devel@nongnu.org; Fri, 17 Jun 2011 10:30:42 -0400 Received: from mail-vw0-f45.google.com ([209.85.212.45]:52916) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QXa4F-0007aO-IL for qemu-devel@nongnu.org; Fri, 17 Jun 2011 10:30:39 -0400 Received: by vws17 with SMTP id 17so877727vws.4 for ; Fri, 17 Jun 2011 07:30:39 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4DFB3734.8080307@redhat.com> References: <4DFB3734.8080307@redhat.com> Date: Fri, 17 Jun 2011 07:39:25 -0400 Message-ID: From: al pat Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] how to verify virtio is being used? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: qemu-devel@nongnu.org Hi Kevin, Thanks! Yes, one disk is visible in guest as sdb (partitioned to sdb1), mounted and I write to it. The virtio disk is visible as /dev/vda, (partitioned to vda1), mounted and I write to it. Kernel log on guest - do you mean dmesg? I was trying to trace through the virt io calls to confirm. and determine the invocation sequence. My lspci output: 00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02= ) 00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] 00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton I= I] 00:01.2 USB Controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01) 00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03) 00:02.0 VGA compatible controller: Cirrus Logic GD 5446 00:03.0 Ethernet controller: Qumranet, Inc. Unknown device 1000 00:04.0 RAM memory: Qumranet, Inc. Unknown device 1002 00:06.0 SCSI storage controller: Qumranet, Inc. Unknown device 1001 lspci -k --- to show kernel drivers associated with the device does not work in the guest. Thanks a On Fri, Jun 17, 2011 at 7:15 AM, Kevin Wolf wrote: > Am 16.06.2011 20:57, schrieb al pat: >> I have posted this on kvm alias, but have not heard back. seeing some in= puts. >> >> seeking some pointers/guidance as to how to determine virtio is being us= ed... >> >> I configured a VM to use block device with if=3Dvirtio (create a 1GB >> disk using dd I exported this disk to the VM and am now doing scp from >> host to the >> =C2=A0guest after creating partition/mkfs. >> >> I created another 1GB disk and export it as a IDE disk. I use the same >> scp command from host to guest after creating partition/mkfs. >> >> I am trying to determine if my block IO is indeed using virtio in the >> first case. >> >> Empirically, I observe that with if=3Dvirtio, the throughput is about >> 30% more (in terms of mbps) and time taken is about 40% less than >> for the case where I passed the disk as a IDE disk. >> >> My scp happens over virbr0 interface (and currently I am not concerned >> if networking is using virtio) >> >> How do I confirm that virtio is being used? Are there any debugs that >> I can enable to do that. > > Have a look at the guest kernel logs, lspci output or just at the device > name: IDE disks are called /dev/sda etc. whereas virtio-blk disks are > called /dev/vda etc. > > Kevin >