On Mon, Mar 4, 2013 at 12:08 PM, Ernesto Domato <edo...@gmail.com> wrote: > On Mon, Mar 4, 2013 at 4:49 PM, Ansis Atteka <aatt...@nicira.com> wrote: >> Though, I do agree that, if Open vSwitch was terminated before libvirt >> for whatever reason, then libvirt still shouldn't hang because of >> that. And on the next startup libvirt should try to clean up whatever >> was left in OVS DB from its previous runs. > > Ok, I already send a patch for libvirt to this list and libvirt list > with a fix that works this way: > > at start up, libvirt runs: ovs-vsctl --no-wait --timeout 5 -- > --if-exists del-port vnet0 -- --may-exist add-port ovsbr0 vnet0 -- set > Interface vnet0 "external-ids:attached-mac=\"52:54:00:FF:D0:9C\"" -- > set Interface vnet0 > "external-ids:iface-id=\"eafbcb1f-3758-e976-015e-7a1f1029b1af\"" -- > set Interface vnet0 > "external-ids:vm-id=\"11245af8-b3ed-0d7c-7fd2-11c692d01da4\"" -- set > Interface vnet0 external-ids:iface-status=active > > The part that I added was the "--no-wait --timeout 5 -- --if-exists > del-port vnet0" portion.
If you do not block on interface creation and libvirt/Open vSwitch init.d dependencies are not right, then I think you might end up with another race condition, where VM automatic start-up would fail. Imagine that: 1. Neither Open vSwitch or libvirt are running 2. libvirt starts up 3. libvirt tries to spin up VM and executes "ovs-vsctl --no-wait --timeout=5 -- del-port ... -- add-port ..." command. After 5 seconds this command times out, because Open vSwitch wasn't running 4. After 6 seconds Open vSwitch starts up, but VM still remains down. This means that you will have to manually start the VM one more time. > > I also added "--no-wait --timeout 5" when libvirt goes down so it can > timeout if ovs-switch is down. Just curious, but wasn't this part already solved with libvirt commit 98e732fc34a47ad9dfdb64aa4207623ee4c1ebcd (network: prevent infinite hang if ovs-vswitchd isn't running)? Are you using libvirt that has this patch? By the way I tried to execute the same commands as libvirt would have executed. Except I ran them directly in the shell. What I observed is that ovs-vsctl did not block indefinitely for this corner case: root@ubuntu:~# service openvswitch-switch stop * ovs-brcompatd is not running * Killing ovs-vswitchd (13202) * Killing ovsdb-server (13193) root@ubuntu:~# ovs-vsctl --timeout=5 -- --if-exists del-port p0 Mar 04 13:39:14|00002|stream_unix|ERR|/tmp/stream-unix.13222.0: connection to /var/run/openvswitch/db.sock failed: No such file or directory Mar 04 13:39:14|00003|reconnect|WARN|unix:/var/run/openvswitch/db.sock: connection attempt failed (No such file or directory) Mar 04 13:39:15|00004|stream_unix|ERR|/tmp/stream-unix.13222.1: connection to /var/run/openvswitch/db.sock failed: No such file or directory Mar 04 13:39:15|00005|reconnect|WARN|unix:/var/run/openvswitch/db.sock: connection attempt failed (No such file or directory) Mar 04 13:39:17|00006|stream_unix|ERR|/tmp/stream-unix.13222.2: connection to /var/run/openvswitch/db.sock failed: No such file or directory Mar 04 13:39:17|00007|reconnect|WARN|unix:/var/run/openvswitch/db.sock: connection attempt failed (No such file or directory) Alarm clock root@ubuntu:~# I tried this with Open vSwitch: 1.4.3-0ubuntu2.1. Are you seeing the same effect with your Open vSwitch? _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
