No irq handler for vector on CentOS 6

If you are getting error messages on the /var/log/messages on your CentOS 6. You may want to see Redhat Bugzilla "No irq handler for vector" error, sluggish system"

Aug 20 11:22:58 node1 kernel: do_IRQ: 2.135 No irq handler for vector (irq -1)

Step 1: Edit Grub Bootloader. Add the pci=nomsi,noaer to the end of the kernel options

# vim /boot/grub.menu.1st

default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS 6 (2.6.32-504.el6.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-504.el6.x86_64 ro root=/dev/mapper/vg_cherry-lv_root rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=vg_cherry/lv_root SYSFONT=latarcyrheb-sun16 crashkernel=128M rd_LVM_LV=vg_cherry/lv_swap rd_NO_DM rhgb quiet pci=nomsi,noaer
        initrd /initramfs-2.6.32-504.el6.x86_64.img

Step 2: Disable irqbalance daemon

# service irqbalance stop
# chkconfig --levels 2345 irqbalance off

Step 3: Reboot the System

# reboot 

References:

1.  Red Hat Bugzilla – Bug 225399
2.  No irq handler for vector