On Sep 4, 2012, at 8:35 AM, Leander Bessa Beernaert <[email protected]> wrote:
> Hello all, > > I've had a few reports from users testing out the sample installation of > OpenStack i setup. The reports were all related to problems with inter-vm > network speeds and connection timeouts as well as the inability to connect to > the outside word from within the VM (e.g.: ping www.google.com). I'm not sure > if i setup something wrong, so i have a few questions. > > The current installation of OpenStack is running with 1 controller node, and > 8 compute nodes. Each node is running Ubuntu 12.04 and Essex with the default > packages. I'm using the VLAN network manager. There is one peculiarity to > this setup. Since each physical hosts only has 1 network interface, i came > up with the following configuration: > - For inter-node communications i set up a VLAN with the ID 107 > - Each tentant has it's private network on a separate VLAN. Currently there > are two tenant, one on VLAN 109 (network: 10.0.9.0/24) and another on VLAN > 110 (network: 10.0.9.0/24). > > I'm not a network expert, so please bear with me if i make any outrages > statements. > > 1) When communicating on the private network, the packets are not routed > through the controller right? That only happens when the VM needs to contact > an external source (e.g.: google), correct? This report originated from users > from VLAN 109. They are using network intensive applications which send a lot > of data between each of the instances. They reported various time-out and > connection drops as well as slow transfer speeds. I'm no network expert, but > could this be related to the routing, VLANs or is it a hardware issue? There are a lot of things that could cause this. You would need to do some extensive debugging to find the source of this. > > 2) I've noticed that for external access (e.g.: google), all the packets seem > to be routed through the nova-network on the controller node. If i setup a > multi-host setup (install nova-network and nova-api-metadata on each compute > node), the external packets no lounger need to be routed through the > controller node right? Correct. You need to set multi_host = true on the networks when you create them as well (or update the flag directly in the database) > > 3) The setup has been running for about 1 month and a half. During that time, > VMs on VLAN 109 could never reach the internet. However, VLAN 110 worked just > fine. Today, out of nowhere, VMs on VLAN 109 can suddenly reach the internet. > I didn't touch or change anything since the initial setup, it simply happend. > Before this bizarre occurrence i've sat down with our network specialist and > told me that, based on the routing rule in iptables, this problem (VMs on > VLAN 109 not being able to connect to the internet) should not be happening. > Has this ever occurred to any of you? This sounds very strange. When I have had issues with certain vlans it has always been forgetting to trunk the vlan on the switch, although vm -> vm communication from one host to another should fail in this case as well.
_______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : [email protected] Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
