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 II] 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 <kw...@redhat.com> wrote: > Am 16.06.2011 20:57, schrieb al pat: >> I have posted this on kvm alias, but have not heard back. seeing some inputs. >> >> seeking some pointers/guidance as to how to determine virtio is being used... >> >> I configured a VM to use block device with if=virtio (create a 1GB >> disk using dd I exported this disk to the VM and am now doing scp from >> host to the >> guest 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=virtio, 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 >
