[libvirt-users] using transport protocol in live migration
Hello, I am working on live migration of virtual machine using xen and kvm.If i use qemu+ssh:///system then is the transport protocol used during live migration tcp or ssh?I mean i want to evaluate the performance of transport protocil during live migration using wireshark and netperf tool,so using this command will show tcp performance? Orelse i will have to use qemu+tcp:/// ?
On 04/12/2013 07:28 AM, digvijay chauhan wrote:
Hello, I am working on live migration of virtual machine using xen and kvm.If i use qemu+ssh:///system then is the transport protocol used during live migration tcp or ssh?I mean i want to evaluate the performance of transport protocil during live migration using wireshark and netperf tool,so using this command will show tcp performance?
Orelse i will have to use qemu+tcp:/// ?
I'd start by reading and understanding this page: http://libvirt.org/migration.html If you do native migration, then it uses whatever protocol the native hypervisor uses (qemu only supports direct tcp), through a separate port. If you use tunnelled migration, then the migration is multiplexed onto libvirt's connection (no additional open port required), and the transport then depends on however you connected to libvirt (whether it is straight TCP or whether it is using SSH depends on the URI of how you connected). Tunnelled migration is inherently slower, since there are more copies involved - qemu -> libvirtd source -> libvirtd destination -> qemu; compared to native migration of qemu -> qemu. But it also provides the possibility of SSH or TLS encryption, if you don't want migration going across the wire unencrypted (since qemu does not yet support encrypted migration natively). -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Thanx. On Mon, Apr 15, 2013 at 8:01 PM, Eric Blake <eblake@redhat.com> wrote:
On 04/12/2013 07:28 AM, digvijay chauhan wrote:
Hello, I am working on live migration of virtual machine using xen and kvm.If i use qemu+ssh:///system then is the transport protocol used during live migration tcp or ssh?I mean i want to evaluate the performance of transport protocil during live migration using wireshark and netperf tool,so using this command will show tcp performance?
Orelse i will have to use qemu+tcp:/// ?
I'd start by reading and understanding this page: http://libvirt.org/migration.html
If you do native migration, then it uses whatever protocol the native hypervisor uses (qemu only supports direct tcp), through a separate port. If you use tunnelled migration, then the migration is multiplexed onto libvirt's connection (no additional open port required), and the transport then depends on however you connected to libvirt (whether it is straight TCP or whether it is using SSH depends on the URI of how you connected). Tunnelled migration is inherently slower, since there are more copies involved - qemu -> libvirtd source -> libvirtd destination -> qemu; compared to native migration of qemu -> qemu. But it also provides the possibility of SSH or TLS encryption, if you don't want migration going across the wire unencrypted (since qemu does not yet support encrypted migration natively).
-- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (2)
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digvijay chauhan -
Eric Blake