Hi,

i'm using several fedora 22 installations under Hyper-V. After updating to the lastest kernel (4.2.7-200.fc22.x86_64) systemd-udevd uses nearly 100% of the CPU. udevadm monitor shows continuously:

´UDEV [1293.873065] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004156 (vmbus)
UDEV [1293.873083] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.873213] remove /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.873280] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004156 (vmbus)
UDEV [1293.873652] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004157 (vmbus)
UDEV [1293.873826] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.874187] remove /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.874473] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.874659] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004157 (vmbus)
UDEV [1293.875033] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004158 (vmbus)
UDEV [1293.875440] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004158 (vmbus)
UDEV [1293.875578] remove /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.875834] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.876169] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004159 (vmbus)
UDEV [1293.876648] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004160 (vmbus)
UDEV [1293.876789] remove /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.876967] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004159 (vmbus)
UDEV [1293.877229] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.877432] remove /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.877724] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004160 (vmbus)
UDEV [1293.877880] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.878213] remove /devices/virtual/misc/vmbus!hv_vss (misc)
KERNEL[1293.878323] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1018806 (vmbus)
KERNEL[1293.878370] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.878660] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004161 (vmbus)
KERNEL[1293.878991] remove /devices/virtual/misc/vmbus!hv_vss (misc)
KERNEL[1293.879069] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1018806 (vmbus)
UDEV [1293.879229] add /devices/virtual/misc/vmbus!hv_vss (misc)
UDEV [1293.879416] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004161 (vmbus)
KERNEL[1293.879505] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1018807 (vmbus)
KERNEL[1293.879538] add /devices/virtual/misc/vmbus!hv_vss (misc)
KERNEL[1293.879919] remove /devices/virtual/misc/vmbus!hv_vss (misc)
KERNEL[1293.879998] remove /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1018807 (vmbus)
UDEV [1293.880308] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1004162 (vmbus)
KERNEL[1293.880406] add /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/vmbus_1018808 (vmbus)

With an older Kernel (for example 4.2.7-200.fc22.x86_64), i don't have any problems. And with fedora 22 with the latest kernel running under ESX, also no problem. So it's the combination of Hyper-V and the latest kernel.

Can someone give me an hint what i can do ?

Greetings

Sven

VSS is the Snapshot service and part of the backup management of hyper v if you go into the settings of your virtual machine in the right hand column select "Integrated Services" under the Management heading then turn off "Backup (Volume Snapshot)". This will stop the problem and CPU use will be back to normal.

1 members found this post helpful.

Hi eddiep06,

that solved the problem. Thanks for the hint !!!