Disk Usage on VPS Showing 98% or more on New VPS with CentOS 6.5 Host Node

(1) Login to the particular Slave node.

Edit /usr/local/solusvm/data/advanced.conf and add the below entry

XENFIXCENTOS6DF="1"

(2) Run the below commands.

wget https://www.dropbox.com/s/j8nu3ye09x9ehwq/command.php -O /usr/local/solusvm/www/command.php
wget https://www.dropbox.com/s/93hsnzzmpwny3r4/solusvmc-xen -O /usr/local/solusvm/core/solusvmc-xen
chmod 6777 /usr/local/solusvm/core/solusvmc-xen

(2) Reboot the VM to reflect the change.

OpenVZ Node within a Xen/KVM host

The default Openvz network setup is designed for when a server is directly connected to a switch.

If you are running OpenVZ on Xen/KVM guest, traffic goes through the Ethernet bridge on the node which is why proxy-arp is needed. By default this is disabled in /etc/sysctl.conf:

net.ipv4.conf.default.proxy_arp = 0

It’s quite rare to have the setup like this.

OpenVZ - Reverse path filtering (rp_filter ) - sysctl.conf

If you come across packet loss problem with the OpenVZ VMs, change rp_filter (Reverse path filtering ) to loose mode (rp_filter = 2) on the hardware node to fix the intermittent network connection loss in the VM's. 

####sysctl.conf variables###
net.netfilter.nf_conntrack_max = 196608
net.nf_conntrack_max = 196608
net.ipv4.conf.default.rp_filter = 2
net.ipv4.conf.all.rp_filter = 2

########################

Dell PERC H200 RAID card (sas2ircu)

Setup CL/i monitoring tool for Dell PERC H200 RAID card (sas2ircu)
=======================================================

Check the status using /usr/sbin/sas2ircu-status

setup script to monitor RAID status
===================================

Bash script to send emails in case of any status change in RAID array.

************************************
#!/bin/bash
EMAIL="test1@dmain.com"
EMAIL1="test2@domain.com"
EMAIL2="test3@domain.com"
rm -f /tmp/alert
/usr/sbin/sas2ircu 0 STATUS > /tmp/alert
diff /etc/orig /tmp/alert
if [ $? -ne 0 ]; then

#Send alert email
/bin/mail -s "RAID status changed on `hostname` -- ( <IP_Address> )" ${EMAIL} ${EMAIL1} ${EMAIL2} < /tmp/alert
fi
************************************

Note: Run the below command and create the file

/usr/sbin/sas2ircu 0 STATUS > /etc/orig

Check HDD health with hardware RAID: MegaCli

(1) Find out the device ID's using MegaCli too

Megacli64 -PDlist -a0|grep Device.Id

Device Id: 7
Device Id: 6
Device Id: 5
Device Id: 4

(2) Check the HDD health on each device using smartctl

smartctl -a -d sat+megaraid,7 /dev/sda|grep 'PASSED\|Reallocated_Sector_Ct\|Temperature_Celsius'
smartctl -a -d sat+megaraid,6 /dev/sda|grep 'PASSED\|Reallocated_Sector_Ct\|Temperature_Celsius'
smartctl -a -d sat+megaraid,5 /dev/sda|grep 'PASSED\|Reallocated_Sector_Ct\|Temperature_Celsius'
smartctl -a -d sat+megaraid,4 /dev/sda|grep 'PASSED\|Reallocated_Sector_Ct\|Temperature_Celsius'