After upgrading from Ubuntu Server 12.04.2 to Ubuntu 14.04.2 Server version, I observed a huge usage of CPU (~ 90%) by systemd-udevd processes (3).
Running udevadm monitor
display continuously following outputs, showing that it always try to add / remove devices :
UDEV [19081.096929] remove /devices/virtual/block/md0 (block)
UDEV [19081.108949] remove /devices/virtual/bdi/9:0 (bdi)
KERNEL[19081.115486] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[19081.115803] add /devices/virtual/block/md0 (block)
KERNEL[19081.116533] remove /devices/virtual/bdi/9:0 (bdi)
KERNEL[19081.116834] remove /devices/virtual/block/md0 (block)
I'm not familiar with all this and I would appreciate to understand what's happening and how to stop that.
How can I fix this problem. Thanks.