How To Tune Your Linux Server Using mlnx_tune Tool

This is a wonderful video from Mellanox

  

How To Tune Your Linux Server Using mlnx_tune Tool from Mellanox Technologies on Vimeo.

Troubleshooting and Error Messages Tips for Platform and OpenLava

Troubleshooting and Error Messages Tips for Platform. But it can be used for OpenLava. Do take a look and digest.

Troubleshooting and Error Messages

udev: renamed network interface eth0 to eth2

I was encountering this error when I start the network

# dmesg |grep eth0 
udev: renamed network interface eth0 to eth2

This occurs when you clone or change the NIC hardware and the OS still retain the old interface information in /etc/udev/rules.d/70-persistent-net.rules.

Just delete /etc/udev/rules.d/70-persisitent-net.rules and reboot the system so the Linux can rebuild the /etc/udev/rules.d/70-persistent-net.rules that match the replaced NIC hardware.

# rm  /etc/udev/rules.d/70-persistent-net.rules
# reboot

Failed to conect to FastX Server

Do take a look at Failed to start a secure connection to the server

Basically, to fix this issue, run the command from your linux machine:

# killall fastx_server 

Relaunch the FastX Client

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