Bugs item #2327497, was opened at 2008-11-22 16:53 Message generated for change (Comment added) made by cova 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: Fabio Coatti (cova) Date: 2008-11-23 16:12 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