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On Monday, December 29, 2014 03:38:40 AM lee wrote: |
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> "J. Roeleveld" <joost@××××××××.org> writes: |
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> > What do you mean with "unusable"? |
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> |
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> The bridge swallows the physical port, and the port becomes |
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> unreachable. IIRC, you can get around this by assigning an IP address |
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> to the bridge rather than to the physical port ... In any case, I'm |
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> finding bridges very confusing. |
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This is by design and is documented that way all over the web. |
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> >> > pass virtual NICs to the VMs which are part of the bridges. |
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> >> |
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> >> Doesn't that create more CPU load than passing the port? |
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> > |
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> > Do you have an IOMMU on the host? |
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> > I don't notice any significant increase in CPU-usage caused by the network |
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> > layer. |
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> |
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> Yes, and the kernel turns it off. Apparently it's expected to be more |
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> advantageous for some reason to use software emulation instead. |
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Huh? That is usually because of a bug in the firmware on your server. |
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> >> And at some |
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> >> point, you may saturate the bandwidth of the port. |
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> > |
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> > And how is this different from assigning the network interface directly? |
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> |
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> With more physical ports, you have more bandwidth available. |
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See following: |
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> >> My switch supports bonding, which means I have a total of 4Gbit/s between |
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> >> the server and switch for all networks. (using VLANs) |
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> |
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> I don't know if mine does. |
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If bandwidth is important to you, investing in a quality switch might be more |
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useful. |
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> >> > But it's your server, you decide on the complexity. |
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> >> > |
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> >> > I stopped passing physical NICs when I was encountering issues with |
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> >> > newer |
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> >> > cards. |
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> >> > They are now resolved, but passing virtual interfaces is simpler and |
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> >> > more |
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> >> > reliable. |
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> >> |
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> >> The only issue I have with passing the port is that the kernel module |
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> >> must not be loaded from the initrd image. So I don't see how fighting |
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> >> with the bridges would make things easier. |
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> > |
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> > Unless you are forced to use some really weird configuration utility for |
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> > the network, configuring a bridge and assiging the bridge in the |
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> > xen-domain config file is simpler then assigning physical network |
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> > interfaces. |
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> |
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> Hm, how is that simpler? And how do you keep the traffic separated when |
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> everything goes over the same bridge? What about pppoe connections? |
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Multiple bridges? |
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-- |
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Joost |
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