I hear you…you want your SQL, DHCP, Hyper-V or other services to be highly available for your clients or your internal users. They can be if you create a Windows Failover Cluster and configure those services in the cluster. By doing that if one of the servers crashes the other(s) one will take over, and users will never even notice. There are two types of Failover Clusters: active/active and active/passive. In the first one (active/active) all the applications or services running on the cluster can access the same resources at the same time, and in the second one the applications or services running on the cluster can access resources only from one node, the other one(s) is/are in stand-by in case the active node is fails.
1 Preliminary Note
Our system's hostname is server1.example.com, and we have a web site www.example.com on it with the document root /var/www/www.example.com/web.
2 Enable The RPMforge Repository
On CentOS 5.2, munin and monit are not available in the default CentOS repositories. Fortunately we can install them from the RPMforge repository. To enable the RPMforge repository, we run
rpm -Uvh rpmforge-release-0.3.6-1.el5.rf.i386.rpm
rm -f rpmforge-release-0.3.6-1.el5.rf.i386.rpm Continue reading “Install Munin on CentOS 5” »
Download memcache plugin memcached.tar.gz the plug-in was found here: http://munin-monitoring.org/browser/trunk/plugins/node.d/memcached_.in.
The alternate download link is Here- memcached.tar
The plug-in is written in Perl and needs the Memcached Perl library installed to communicate with memcache.
~$ apt-get install libcache-memcached-perl
~$ tar -zxvf memcached.tar.gz
~$ cp memcached_ /usr/share/munin/plugins
~$ ln -s /usr/share/munin/plugins/memcached_ /etc/munin/plugins/memcached_rates
~$ ln -s /usr/share/munin/plugins/memcached_ /etc/munin/plugins/memcached_bytes
~$ ln -s /usr/share/munin/plugins/memcached_ /etc/munin/plugins/memcached_counters
~$ /etc/init.d/munin-node restart
I have implemented this on Debian 6 (Squeeze system) with the IP address 192.168.0.100 where I’m logged in as root.
Installing VirtualBox To install VirtualBox 4.1 on our Debian server, we open /etc/apt/sources.list… added this line-
deb http://download.virtualbox.org/virtualbox/debian squeeze contrib non-free
Use appropriate OS source list from https://www.virtualbox.org/wiki/Linux_Downloads
Then we download the VirtualBox public key…
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | apt-key add -
… and update our package database: sudo apt-get update
Afterwards, we install VirtualBox 4.1 as follows:
apt-get install linux-headers-$(uname -r) build-essential virtualbox-4.1 dkms
(The dkms package ensures that the VirtualBox host kernel modules are properly updated if the Linux kernel version changes.) Starting with version 4.0, VirtualBox has introduced so called “extension packs” and has outsourced some functionality like remote desktop connection support (VRDP) that was part of VirtualBox packages before version 4.0 into these extension packs. Because we need remote desktop connections to control our virtual machines, we need to install the appropriate extension pack now. Go to http://www.virtualbox.org/wiki/Downloads, and you will find a link to the following extension pack: VirtualBox 4.1.18 Oracle VM VirtualBox Extension Pack Support for USB 2.0 devices, VirtualBox RDP and PXE boot for Intel cards. Download and install the extension pack as follows:
VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-4.1.18-78361.vbox-extpack
(Make sure you grab the latest version from the VirtualBox web site.) Restart the Server at this stage to update the kernel with virtualbox optimized. Installing phpvirtualbox First create a system user called vbox and add it to the vboxusers group:
useradd -m vbox -G vboxusers
Create a password for the vbox user:
Create the file /etc/default/virtualbox and put the line
in it (so that the VirtualBox SOAP API which is called vboxwebsrv runs as the user vbox): vi /etc/default/virtualbox VBOXWEB_USER=vbox Next create the system startup links for vboxwebsrv and start it:
update-rc.d vboxweb-service defaults
Now, run the following command to check if virtualbox kernel modules are loaded or not.
sudo systemctl status vboxdrv
sudo /etc/init.d/vboxdrv status
vboxdrv.service - VirtualBox Linux kernel module Loaded: loaded (/usr/lib/virtualbox/vboxdrv.sh; enabled; vendor preset: enabled) Active: active (exited) since Thu 2015-11-26 16:38:30 IST; 42s ago Nov 26 16:38:29 server systemd: Starting VirtualBox Linux kernel module... Nov 26 16:38:30 server systemd: Started VirtualBox Linux kernel module. Nov 26 16:38:30 server vboxdrv.sh: Starting VirtualBox kernel modules.... Hint: Some lines were ellipsized, use -l to show in full.
If it, not loaded, run the following command to load them:
sudo /etc/init.d/vboxdrv setup
We need a web server with PHP support to serve phpvirtualbox – I’m using Apache2 here. Install Apache2 and PHP5 as follows:
apt-get install apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common apache2 apache2-doc apache2-suexec libapache2-mod-php5 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libapr1 php5-common php5-mysql php5-suhosin php-pear wget
for Ubuntu you may install Apache-PHP with folliwng packages-
apt-get -y install apache2 php5-mysqlnd php5-curl php5-gd php5-intl php-pear php5-imagick php5-imap php5-mcrypt php5-memcache php5-ming php5-ps php5-pspell php5-recode php5-snmp php5-sqlite php5-tidy php5-xmlrpc php5-xsl php5 libapache2-mod-php5
For Ubuntu 16 use the following packs:
apt-get install php libapache2-mod-php php-mcrypt php-mysql php-xml php-soap
Now, start vboxweb-service, and make it to start automatically on every reboot.
sudo systemctl status vboxweb-service
sudo /etc/init.d/vboxweb-service start
Starting VirtualBox web service ...done.
I want to serve phpvirtualbox from Apache’s default virtual host with the document root /var/www (I will install it in /var/www/phpvirtualbox) – if you have a different document root, you must adjust the following steps: cd /var/www wget http://phpvirtualbox.googlecode.com/files/phpvirtualbox-4.1-7.zip Unzip phpvirtualbox and rename the phpvirtualbox-4.1-7 to phpvirtualbox for ease of use: unzip phpvirtualbox-4.1-7.zip mv phpvirtualbox-4.1-7 phpvirtualbox Next go to the /var/www/phpvirtualbox/ directory… cd /var/www/phpvirtualbox/ … and create the file config.php by copying it from config.php-example: cp config.php-example config.php Open config.php and fill in the password you created earlier for the vbox system user: vi config.php […] /* Username / Password for system user that runs VirtualBox */ var $username = ‘vbox’; var $password = ‘secret’; […] That’s it already – you can now open a browser and access phpvirtualbox as follows:
Removing & updating Virtualbox Extension Pack:
For example removing virtualbox extension pack 4.3 to 5.1 version, do the following things-
$ VBoxManage list extpacks Extension Packs: 1 Pack no. 0: Oracle VM VirtualBox Extension Pack Version: 4.1.12 Revision: 77218 Edition: Description: USB 2.0 Host Controller, VirtualBox RDP, PXE ROM with E1000 support. VRDE Module: VBoxVRDP Usable: true Why unusable:
How to remove an extension pack:
$ VBoxManage extpack uninstall "Oracle VM VirtualBox Extension Pack" 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% Successfully uninstalled "Oracle VM VirtualBox Extension Pack".
This is a very important page that and for some reasons I just forget the links on nagios-
Some very basic links that I should bookmark immediately-
Well, install squint is quite simple! But installing squish is quite tricky- the document provided is not sufficient to cover few steps. I’ll try to summerize it (I’ve tested it on FC-5 distro)-
Just a small tweaking comnand that allows MySQL server on a linux server to open & listen to port 3306 for remote connectivity-
[root@linux root]# iptables -I INPUT -p tcp –dport 3306 -j ACCEPT
Quotas on Linux are tricky, not because they are difficult to setup, but because they are so poorly documented, and what documentation exists is more often than not incorrect to the point of not working. If you are using a relatively recent Linux version, the following instructions should work without difficulty.
Prior to Linux Installation:
Yes, a major & key point in Linux Partition is /home directory.
VHost is widely setup on almost all control panel mechanism on /home location, since
– Users & Groups
– FTP server
– User shell
– Apache and all that other directives are constructed on this /home partition
So, home should be created as a Logical Volume on a Linux native File system (ext3). In my later section, I’d assume there is already a /home partition (and it’d also wise to have this partition as much disk space as you want to give away to your clients. Because, even mails and even mysql data will also be stored in this volume.
System > Disk & Network Filesystems
On the System > Disk & Network Filesystem you’ll get something like this-
On the “Mounted As” column select “/home” to go to next screen which is similar as below-
Down below to “ext2/ext3 specific options section” look for the options “Use Quotas?” and select “User and Group” from the drop down menu.
Click “SAVE” and you’re almost done!
System > Disk Quotas
Once you completed the above step, you should find something similar like-
On “Action” column, click “Enable Quotas”
You’re done! And that’s it! I’m sorry nothing more to do.
Are Quotas Working?
To test to be sure your quotas are actually enabled, you can use the “repquota /home” utility to see what the current quota usage looks like. It should looke something like this:
Step by step installation (Complicated and usually I do not follow) guide available on the followin URL-
Method-2: (My Way):
Installation within Webmin.
- Under “Un-used Modules” from the left frame
- “Usermin Configuration” hyper link
- “Install usermin RPM package“
Actually there’s nothing much to configure on usermin other than setting up webmail and few links not to show your clients!
After installation- it is very hard to locate Usermin within Webmin! but you can find them 🙂
- You can find usermin by typing “usermin” from the webmin search box
- You can directly access the Usermin module by http://IP:10000/usermin
But do no access to http://IP:20000 the usual usermin client panel- you can not configure usermin module from here. You can configure once you are logged in to webmin framework.
You can customize your usermin whatever fits your need. I did the following from my setups-
- Usermin Module coniguration > Read Mail
Sendmail mail file location = /home/mail
Mail storage format for Inbox = Sendmail style single file (mbox)
Mail subdirectory style= mail/username
- Available Modules (see the scrren shot)
That’s it! Seeya in the next chapter 😐