On 8/17/15 3:47 , Schmurfy wrote: > Hi, > We recently bought a HP DL120 G9 which appears to have an i350 network > card, we planned to use it as a SmartOS Host running kvm virtual machines > but we have weird behavior with the network. > > What we see is high latency variation on load and occasional losses, when > sending pings to both the host (Smartos) and the KVM VM the latency for the > host is highly stable (below 3ms) with no loss while the VM results are > scary (up to 20ms latency with some losses). > > To be sure I created a bare VM with nothing on it and left it durring the > weekend with a ping to it, the results are what I saw with the other VM: > high latency variation and losses (without any load on the Host or VM). > > Is there any known issue with this card and KVM ? (it uses the igb driver), > does someone else successfully uses it ?
Hi, We've used the i350 quite a lot in various generations of hardware; however, we haven't been running it with KVM. The first thing you might want to check is where the latency is coming from. Whether we're getting backed up somewhere or something else is going on. To do that, I might loook at DTracing through various parts of the MAC stack and seeing what, if any hardware rings and fanout is being done in MAC. For techniques on how to do this kind of diagnosis, take a look at https://smartos.org/bugview/OS-4008 where I did this for overlay networks and take a look at http://src.illumos.org/source/xref/illumos-gate/usr/src/uts/common/io/mac/mac_sched.c#29 which I wrote as part of doing the previous analysis to explain how the data path works. Robert ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
