Mitigating the CentOS 6.5 Network-adapter-reset Bug

We have confirmed that the CentOS 6.5 kernel (x86_64) has a flaw that causes some network adapters to reset, making them unavailable unless you do a system reboot. You would likely see the message “eth0: Reset adapter unexpectedly” in your system logs when this issue occurs. This bug has also been reported in the CentoOS Bug Tracker forum as early as December 2013.

To prevent this reset, add “pcie_aspm=off” to the kernel command line parameters by doing either of the following actions:

  • Using the Grubby command line tool: /sbin/grubby –args=pcie_aspm=off –update-kernel=ALL 
  • Using your text editor to edit /boot/grub/grub.conf (i.e. vim /boot/grub/grub.conf) so you can add the required parameters to at least the first (default) item in the menu

Example:

default=0

timeout=5

splashimage=(hd0,0)/grub/splash.xpm.gz

hiddenmenu

title CentOS (2.6.32-431.1.2.0.1.el6.x86_64)

        root (hd0,0)

        kernel /vmlinuz-2.6.32-431.1.2.0.1.el6.x86_64 ro root=/dev/mapper/VolGroup00-root nomodeset rd_NO_LUKS LANG=en_US.UTF-8 console=tty0 rd_NO_MD rd_LVM_LV=VolGroup00/swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup00/root  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet pcie_aspm=off

        initrd /initramfs-2.6.32-431.1.2.0.1.el6.x86_64.img

title CentOS (2.6.32-431.el6.x86_64)

        root (hd0,0)

        kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup00-root nomodeset rd_NO_LUKS LANG=en_US.UTF-8 console=tty0 rd_NO_MD rd_LVM_LV=VolGroup00/swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup00/root  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

        initrd /initramfs-2.6.32-431.el6.x86_64.img

Reboot the system to load the kernel with the new parameters.

See our Knowledgebase for more How-To articles.

Comments are closed.