kernel-packages team mailing list archive

[Tamas Papp <1341195@xxxxxxxxxxxxxxxxxx>]

On 07/16/2014 06:35 PM, Serge Hallyn wrote:


> To be clear, you have not yet gotten the bug since you've set
> KSM_ENABLED to 0, or have you?

I just did it, so no, not yet.

This happened by time:

Saucy (everything is fine) -> Trusty (issue happened) -> Trusty with 
Saucy kernel 3 weeks ago (no issue) -> today with 3 weeks uptime (issue 
happened) -> KSM_ENABLED=0 + reboot with Trusty kernel -> now

I just want to be clear, that both of us understand the same on this.


> Interesting about the saucy kernel.  Ideally we could reproduce this
> reliably enough to really bisect.
>
> I wonder if we can reproduce without qemu.


I have a some other servers with LXC with no issue, If there is KVM, 
then issue happens.
Does it really not show up anywhere else?

sysctl.conf:

kernel.printk = 3 4 1 3
net.ipv4.conf.default.rp_filter=1
net.ipv4.conf.all.rp_filter=1
net.ipv4.tcp_syncookies=1
net.ipv4.conf.all.secure_redirects = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.all.accept_source_route = 0
net.ipv6.conf.all.accept_source_route = 0
kernel.shmmax=335544320000
net.ipv4.tcp_rmem = 4096 16777216 33554432
net.ipv4.tcp_wmem = 4096 16777216 33554432
net.ipv4.tcp_mem = 4096 16777216 33554432
net.core.rmem_default = 16777216
net.core.wmem_default = 16777216
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 30000
net.core.netdev_max_backlog = 30000
net.ipv6.neigh.default.gc_thresh1 = 512
net.ipv6.neigh.default.gc_thresh2 = 2048
net.ipv6.neigh.default.gc_thresh3 = 4096
vm.swappiness = 1

fs.inotify.max_user_watches = 81920
fs.inotify.max_user_instances = 1024

May that be important?


tamas

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1341195

Title:
  KVM guests getting slow by time

Status in “linux” package in Ubuntu:
  Incomplete
Status in “qemu” package in Ubuntu:
  Incomplete

Bug description:
  There is a post with very similar symptoms on serverfault:

  http://serverfault.com/questions/609881/windows-server-2012-on-kvm-on-
  ubuntu-14-04-runs-well-for-a-while-and-then-slows/612084#612084

  
  Basically all kind of KVM guests are getting slow by time, both windows or linux. The more running guests, it happens sooner.
  Switching back to Saucy kernel is a good workaround.

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: qemu-kvm 2.0.0+dfsg-2ubuntu1.1
  ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
  Uname: Linux 3.13.0-29-generic x86_64
  NonfreeKernelModules: zfs zunicode zavl zcommon znvpair
  ApportVersion: 2.14.1-0ubuntu3.2
  Architecture: amd64
  Date: Sat Jul 12 22:18:49 2014
  SourcePackage: qemu
  UpgradeStatus: No upgrade log present (probably fresh install)

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