Bugs item #2327497, was opened at 2008-11-22 07:53 Message generated for change (Comment added) made by jiajun You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2327497&group_id=180599
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None >Status: Open Resolution: None Priority: 5 Private: No Submitted By: Jiajun Xu (jiajun) Assigned to: Nobody/Anonymous (nobody) Summary: NFS copy makes guest network unstable Initial Comment: The NFS network of KVM guest is very unstable. When we copy a >600M file to the guest by NFS mount. The guest's network will down after finishing at about 500M size. Then, guest's network is down. Host also can not use "ping" or "scp". And sometimes, host also complains: ping: sendmsg: No buffer space available. I see memory by 'free', there is only 69MB free (While totally 8GB on the machine!). Using scp to copy file can not reproduce it. This issue is very easy to be reproduced (>50%). Reproduce steps: ---------------- 1. Create a guest and config NFS sharing folder on it 2. Mount the nfs folder to local folder --- /media 3. cp xxx /media 4. After some time, guest network is down ---------------------------------------------------------------------- >Comment By: Jiajun Xu (jiajun) Date: 2008-11-26 19:43 Message: We tried e1000, virtio and 8139cp driver. No such issue found. Seems the issue only occur with 8139too driver. ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2008-11-25 01:47 Message: I tested overnight with e1000, 2.5TB and still going. Please retest with e1000. ---------------------------------------------------------------------- Comment By: Fabio Coatti (cova) Date: 2008-11-24 07:47 Message: I wouldn't be so sure of 8139 culprit. We are seeing this with e1000 and virtio driver... ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2008-11-24 07:31 Message: Seems to be a bug in the 8139too driver. Please try with the 8139cp driver (which has much better performance). ---------------------------------------------------------------------- Comment By: Jiajun Xu (jiajun) Date: 2008-11-23 23:01 Message: We did not test such case before. I think the issue also exists before. ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2008-11-23 13:13 Message: It's almost certainly a problem with the qemu process, not the bridge. ---------------------------------------------------------------------- Comment By: Fabio Coatti (cova) Date: 2008-11-23 12:15 Message: I can't find out easily wich kvm version worked (nor be sure that is kvm executable itself to have issues), as the subsystems involved are quite a lot an some time passet prior to spot the problem. (kvm itself, network birdge, host kernel may be involved, of course). Now I'm trying to find out the combination that worked, but at the same time I'll be willing to do some tests to discover (on the actual non working setup) some hints, as the bisection can be a very daunting task. (this issue has been noticed after several upgrades). ---------------------------------------------------------------------- Comment By: Avi Kivity (avik) Date: 2008-11-23 10:40 Message: Is this a regression, or a new test? It it is a regression, what was the last version that worked? ---------------------------------------------------------------------- Comment By: Fabio Coatti (cova) Date: 2008-11-23 07:12 Message: I can confirm a similar behaviour: a kvm machines gets large amounts of data via http protocol and saves that files over NFS. (file sizes are in the range of 4-20 MB approx and the machine downloads several of that files.) After some time (I don't have a precise figure, but some hundreds of MB) the guest nework goes down. No answers even to ping coming from outside. the guest uses virtio network drivers (as normal drivers are way too slow) host machine: 64 bit AMD dual quad core 16GB, tried with several kernels ranging from 2.6.27.4 to 2.6.25.19 guest: 32 bit kvm machines (tried 76/77/78 ). both UP and SMP configuration. kernels: same as host machine network setup: bridged network with br0 device on host machine. We are using 2 vlans for guest and we have tried all the configuration (single tap and vlans resolved on guest side,then two tap so two interfaces on guest machine and so on) without any improvement. I can exclude MTU issues, as we have seen that and solved, this issue is completely different. At some point, sniffing traffic on host interfaces we are able to see only ARP requests coming from guest, nothing more. I understand that data is in no way complete, but I'm willing to do any debug if someone gives me any hint on how to do so correctly. Thanks. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2327497&group_id=180599 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
