Linux has a nice feature called “AutoFS” which allows the system administrator of a workstation to configure remote or local file systems mounting options for all users (even non-adminsitrator) to use. New file systems to be automatically mounted are found in the “/misc” directory. Normally, without AutoFS configured and working, this directory should be...
This article demonstrates the process of encrypting a partition using LUKS on a Redhat or CentOS system. lsmod | grep dm_crypt If there is no output from the above command, go ahead and load the modules needed – as follows. Otherwise skip this step (consider adding the following line to your “/etc/rc.local” file so...
These are the steps to install the RHEV packages on a RHEL 6.x server. 1. Install the RHEL server. It doesn’t matter which packages were selected during installation. 2. Go to the website “http://rhn.redhat.com” and login. 3. Go to “Systems” and click on the server that you’d like to install the RHEV suite on....
Use the following IPTables rules “/etc/sysconfig/iptables” on a Redhat/CentOS system where this system is a KVM host with KVM guests running. It’s a test script which is known to work. KVM guests often have networking troubles through the fault of the host. First backup your IPTables firewall: cp /etc/sysconfig/iptables /etc/sysconfig/iptables.backup Now apply the following...
This article demonstrates how to create a KVM virtual machine using the “virt-install” tool. The Here is a sample command which will create a new VM with the following attributes: Machine name = MyLinuxServer Memory/RAM = 1024 MB Disk format = qcow2 Disk size = 10GB Disk path = /home/libvirt/images/MyLinuxServer.img ISO to install from...
It’s not a matter of running YUM to install Asterisk on Redhat or CentOS. Instead, you need to compile it yourself. But don’t worry. It’s a simple process and will only take a few minutes. First make sure you have the required tools to compile Asterisk: yum install gcc gcc-c++ make openssl-devel newt-devel ncurses-devel...
Apt-get can source from files and ISOs where the ISO has been mounted locally. This HowTo will demonstrate how to add an ISO location which also covers the local file location. First, mount the ISO: mount -o loop /home/iso/ubuntu-11.04-server-amd64.iso /media/iso Next, backup the exiting “/etc/apt/sources.list” file: cp /etc/apt/sources.list /etc/apt/sources.list.orig Now add the following line...
On CentOS, the virsh command is used to control KVM VM guests. This article demonstrated the process of creating a snapshot of a VM guest in the qcow2 format. You can list your VM guests using the following command: virsh list --all Now create a snapshot using the name of the virtual machine derived...
The KVM image format RAW (the default) is very basic. One feature that might be missed is the ability to Snapshot the entire virtual machine. The Qcow2 format supports snapshots. The following command will convert a KVM image from RAW to Qcow2. qemu-img convert -f raw -O qcow2 /home/libvirt/images/vmguest1.img /home/libvirt/images/vmguest1.qcow2 In the above command,...
To find the number of physical CPU’s on the motherboard, not just cores, try the following command (you must be root to run this command): dmidecode --type 4 | grep -c Socket The output will be a number by its self. Such as “1″ or “2″ specifying the number of physical CPUs.
Use with respect. This script shows an inefficient (but quick and useful) method of testing a Windows share from a Linux host. The script is written with BASH in mind. The script uses a password file (not included) to guess. A Windows server (or any SMB/CIFS) server would easily repel such a penetration test...
PPTPd VPNs use the TCP port 1723 and the GRE protocol. This is an example only and you should either modify your existing firewall (using appropriate tools) or build on this example to create a new firewall script. Create the firewall script file. touch /usr/bin/firewall.sh chmod 755 /usr/bin/firewall.sh Add the following content to the...
Debian and Ubuntu have “apt-get” to help with the PPTPd installation. CentOS and RedHat aren’t so easy. These instructions show how to install PPTPd (poptop) on CentOS. For CentOS 6, consider compiling PPTP and PPP from source. See Ubuntu instructions here. This article is based on the great work from “http://www.rockia.com/2010/10/easy-installation-of-pptp-vpn-server-on-centos”. Download the required...
This article shows a basic Asterisk 1.8.8 configuration. This article doesn’t cover installation. However, on Ubuntu, Asterisk can be installed via APT. Redhat is not so simple. In fact, in a recent CentOS 6.1 installation on which we needed Asterisk 1.8.8, it was simpler to compile from source than attempt an RPM installation. Our...
This is an example of a firewall running on a CentOS server running Asterisk 1.8.8. The firewall is IPTables. All IP phones using this Asterisk server are internal and not connecting directly to the server from the Internet. Although, this is not a problem if the phones are accession the Asterisk server via a...
Home networks can have multiple access points to improve coverage. High-end access points allow centralised configuration and security which is suitable for enterprise use. For home use, any access points are fine as long as they are properly configures. The goal should be to allow a laptop or other portable device to “roam” around...
When Gnome is missing the top and bottom menu bars, you should install two extra packages: yum install -y gnome-globalmenu-common gnome-applet-globalmenu Or you can install all Gnome packages as follows (warning, it installs a lot of packages…): yum install -y gnome-* Restart your Xorg session. Either way you will gave a working Gnome environment...
This article explains how you (the system administrator) can control servers using just your smart phone. Simply, you’ll install Webmin with a theme designed for mobile devices. Install Webmin using this HowTo: http://www.agix.com.au/blog/2011/04/installing-webmin-on-ubuntu/ Next, install the mobile theme located here: http://www.webmin.com/mobile.html Next, turn on the theme within Webmin by following these steps: 1. Log...
This article demonstrates how to install RPM packages from a file containing a list. For example, the following command generates a list of installed RPM packages: rpm -qa The same command but output the list into a file: rpm -qa > rpm.list Now we can install the list of RPM packages based on the...
SELinux is a security feature that allows administrators to greatly enhance a servers security. Essentially, SELinux is an add-on that prevents users and programs from breaking defined access rules. Redhat and CentOS come with SELinux enabled by default. However, it’s too often disabled to allow easier system administration. This article explains a few basics...
This HowTo explains the process of reinstalling all installed packages on a Ubuntu system. Read the whole article if you don’t have Internet access and you intend to use a CD-ROM. First you need a list of currently installed packages: dpkg --get-selections > /tmp/agix.apts Now run the following to reinstall the listed packages: dpkg...
This HowTo gives instructions on installing and running rkhunter to find and help remove root kits on Linux systems. First, download and install rkhunter: apt-get install rkhunter Edit the configuration files “/etc/rkhunter.conf” to look like this (but with a different email address for warnings to be sent to): ROTATE_MIRRORS=1 UPDATE_MIRRORS=1 MIRRORS_MODE=0 MAIL-ON-WARNING="support@agix.in" MAIL_CMD=mail -s...
RedHat use Grub version 0.97. Grub version 2 is slightly different. This HowTo was tested on CentOS 6. Warning: Consider allowing your computer to boot from CD or USB just in-case you break your Grub. You will want the option to correct your “/boot/grub/menu.lst” file if all goes bad. Knoppix or another live distribution...
This article explains how to configure a very basic but functional Squid web proxy. Install squid: apt-get install squid Edit the “/etc/squid/squid.conf” configuration file. The following is all that is needed: acl all src all http_port 3128 access_log /var/log/squid/access.log squid hosts_file /etc/hosts http_access allow all Restart squid: /etc/init.d/squid restart Configure web browsers (Internet Explorer,...
Apache2 has the ability to host multiple websites using just the one Apache2 server. There are several ways to do this and we’ll focus on the “NameVirtualHost” method. Simply put, NameVirtualHost allows one web server to use one IP address to server multiple websites. Edit your first website configuration file by editing the file...
This HowTo demonstrates the process to recover a Cisco router password using Linux. You will need the serial cable that probably came with the router. Laptops don’t often come with serial ports so you may need a usb-to-serial adaptor. Install minicom: apt-get install minicom Get the serial port to use: dmesg | grep ttyS...
This tutorial explains how to configure Apache2 to host websites accessible via SSL (secure connection). Start by installing Apache2: apt-get install apache2 Run the following commands. The OpenSSL commands require your interaction to create the certificates with the appropriate values. openssl genrsa -des3 -out agix-server1.key 1024 openssl req -new -key agix-server1.key -out agix-server1.csr openssl...
This HowTo explains how to configure Apache2 server to authenticate user access using LDAP as the back-end. First, install both LDAP and Apache2 using the HowTo’s below: Note: you don’t need to read the following two articles if you already have Apache installed and an LDAP server on your network to authenticate against. Installing...
This article explains how to add extra security to your computing environment by encrypting your backups as you make them. The encryption used in this HowTo is “symmetric” and does not use keys. You might prefer to use keys which makes the process even safer. Using a pass-phrase rather than keys makes it easier...
Actually, we’ll use GPG. PGP means Pretty Good Privacy. GPG is the GNU (free) version. They both do the same thing, encrypt your data. The best type of encryption is known as “public key encryption”. It requires the sender to encrypt a file with the receivers public key. The receiver decrypts the file with...
This article explains how to monitor a Linux systems network interfaces. Install BMon using the following command: apt-get install bmon Now run “bmon” to see something similar to the following: interface: lo at www.agix.in bmon 2.0.1 # Interface RX Rate RX # TX Rate TX # www.agix.in (source: local) 0 lo 0.00B 0 0.00B...
This article explains how to install ProFTP on a Ubuntu server and use a per-existing LDAP server for authentication. If you intend to configure the LDAP server too, consider this article which is perfect for FTP server authentication. First install proftp with the LDAP module: apt-get install proftpd-mod-ldap Uncomment the following line from the...
This article explains how to install OpenLDAP on Ubuntu to store user, group and contact information. This HowTo stops short of allowing people to log into the local system because when writing this article i needed an LDAP server for authentication and contact information for remote systems (FTP and phone directory). You will be...
This article explains the process for restoring data on a Linux server. Linux administrators typically find them selves in one of two situations when faced with a restoration situation. The first is a simple situation where a user has deleted something accidentally and now needs it back. The second situation is when the operating...
Windows 7 works fine with Samba but you do need to make a registry change. Fortunately you can do this by running a “reg” patch which takes just a few seconds. Make sure you have the latest version of Samba. It doesn’t matter what password database back-end you’re using. Earlier versions of Samba do...
The good people on the Ubuntu team have made it very easy to install Java JDK using apt-get. Simply run this command as root (or SUDO): apt-get install openjdk-6-jdk No need to modify the repositories. Note that the version may change.
This tutorial walks through the process of extending an existing LVM to include an additional partition. The new partition can be on a new hard disk or on the same hard disk as the existing partitions that the LVM is on. See a basic introduction to LVM here: Using LVM2 On Linux In this...
“phpmyadmin” is a tool that allows the administrator to manage MySQL databases via a web interface. Start by installing it using Apt Get: If you don’t already have a working web-server and MySQL database on this server, you should install them: apt-get install apache2 apt-get install mysql-server mysql-client Now run the following to install...
The “logger” tool is used to send log entries to the syslog system. It’s very simple to use: logger The backups have started! The above will put the following into your systems log file “/var/log/messages”: Jun 26 21:13:12 MyServer root: The backups have started! So what does the above mean? The date and server...
Wireless networks are great when they work. But when they don’t work, they can be simply annoying. They are difficult to troubleshoot because the cause of the problem may be your neighbors microwave, your child’s hand held game, your mobile phones Bluetooth device or your cordless phone. The problem of wireless “drop outs” is...
This article demonstrates how to test that an SMTP server is working by using the Telnet commend. It’s also a good way to learn how SMTP works. In this example, the email subject is “This is a test” and the body of the email is “bla”. The “.” following “bla” signifies the end of...
This article explains how to remove a NAT entry from a Cisco router that is currently in use. For example, if you try to remove an existing NAT entry that the router is currently using: no ip nat inside source static tcp 10.1.1.1 80 192.168.1.55 80 You may get the following error: Dynamic mapping...
This article demonstrates how to change the case of a column in MySQL to lower or upper case. You need to have update access to the table. To change the case of the column “MyColumn” to lower case: UPDATE MyTables SET MyColumn=LOWER(MyColumn) To change the case of the column “MyColumn” to upper case: UPDATE...
This article shows how to disable the cache logging feature of Squid. The “/var/log/squid/cache.log” file can grow huge depending on your logging settings within the “/etc/squid/squid.conf” file. Also, this file has very little to offer you as the administrator. To disable Squid cache logging, add the following line to the top of your “/etc/squid/squid.conf”...
This article demonstrates sending an email from the Linux command line with an attachment. This is useful when used in a script. First you need Mutt: apt-get install mutt Now you can run the following: mutt -a /etc/resolv.conf support@agix.com.au -s "Test 1" < /dev/null The above example will send the file “/etc/resolv.conf” to the...
This article demonstrates the use of the LOG option in IPTables to show which of your rules is getting hits. The following is a very basic IPTables firewall which we will build on: #!/bin/bash # Set defaults. iptables -F iptables -X iptables -P INPUT DROP iptables -P OUTPUT ACCEPT iptables -P FORWARD ACCEPT #...
This article gives a few useful tcpdump examples. Tcpdump is a Linux network packet analyser. Using Tcpdump, the system administrator can see packets of data coming in and going out of a Linux system. Tcpdump is a great tool for network based application troubleshooting. Listening to packets on “eth0″: tcpdump -i eth0 Listening for...
Most Unix installs include an application called Mail, which can be used as a simple way to send emails to other users on a system, or via SMTP to physical email addresses. The simplest way to send a plain text email, is to use the guide as follows. Once you’ve finished the body of...
From Wikipedia: An Apple Disk Image is a proprietary disk image format commonly used with the Mac OS X operating system. The format allows secure password protection as well as file compression and hence serves both security and file distribution functions; it is most commonly used to distribute software over the Internet. Newly created...
This HowTo demonstrates the Samba “Virtual Server” feature. A feature that allows a single Samba server to appear to the LAN as multiple servers. This can be usefull if two companies share the same office space and want to save money or when two companies merge. Consider this HowTo to catch up with the...
This HowTo demonstrates how to configure dynamic DNS using Bind9 and DHCPd on Ubuntu Linux. The goal is to allow the DHCP server to update DNS zone(s) with new host leases. In this example, the DHCP and DNS servers are running on the same system. Note that this article doesn’t include reverse DNS settings....
http://www.agix.com.au/flow-servers.html We’ve upgraded out site to include our new product range of Flow Servers. AGIX offers two product, both developed in-house. The Flow Internet filter server and the Flow SBS server. Both systems are built on Linux and highly customised to suit the clients needs. The Flow Internet filter is a highly features Internet...
This tutorial shows how to find Windows computers on your LAN, find their shares, mount them and then copy (rsync) their content to a central Linux computer. This could be part of your backup solution assuming you backup desktop computer contents. The entire process is scripted below. Make sure: 1. That your Linux computer...
Why Use Linux In Your Small Business? Click here. Linux is becoming more common in the small business place due to it’s low cost of ownership and it’s wide feature-set. While Linux makes a great Domain Controller (along with DHCP, DNS and Web Proxy) it lacks in the Calendar and Contacts areas. But combine...
A regularly asked question is “how do you protect your linux machine from brute force SSH attacks?” with a seemingly infinite number of potential solutions ranging from: Setting ssh to only accept logins from specific users Setting ssh to NOT allow incoming connections from root Setting ssh to only accept incoming connections from specific...
This article explains how to use IPTables to do one-to-one NAT’ing. For example, we have two public IP addresses and each will be NAT’ed to a different internal host. “Public IP addresses” to “inside hosts” translations: From 10.2.3.4 : To 192.168.0.4 From 10.2.3.5 : To 192.168.0.5 The following two lines should be added to...
When using Linux as a firewall/router, the administrator can terminate a TCP session by using the Cutter command. Cutter works by sending each party (the source and destination) an RST packet. RST packets inform the hosts that something has gone wrong and the session is terminated as a result. Install Cutter: apt-get install cutter...
Nmap is capable of scanning a remote computer and returning its operating system. Consider the following example: nmap -O 192.168.0.1 -p22 --system-dns In the above example, the remote system (192.168.0.1) is scanned. Port 22 (-p22) is specified but only to prevent Nmap from scanning all of them. The -O option instructs Nmap to do...
This HowTo explains how to recover from a Windows XP error such as “Windows could not start because the following file is missing or corrupt: WINDOWSSYSTEM32CONFIG” using Knoppix Linux. You will need a copy of Knoppix from “http://www.knoppix.de”. 1. Boot into Knoppix and choose to start a “SHELL”. 2. Mount the local hard disk...
This HowTo explains how to manage a Windows (Samba) domain using Webmin. User management usually involves password changes, group membership changes, joining new computers to the domain and creating new user accounts. This HowTo discussed the day to day maintenance tasks and how Webmin can help. Be sure that your Linux and Samba system...
This HowTo simply walks through the installation process for Webmin. Webmin is a web-based system administrator tool or Linux. Start by downloading the package from the Webmin website. For this tutorial, the following was used: cd ~ wget http://downloads.sourceforge.net/project/webadmin/webmin/1.540/webmin_1.540_all.deb Now install the package: dpkg -i ~/webmin_1.540_all.deb On Ubuntu 10.10, the above command completed with...
If you’re a Windows administrator, you’ll no doubt be familiar with the Windows RDP Remote Desktop tools – otherwise known as Terminal Server. Linux administrators usually use SSH for command-line control of their Linux servers. But if desired, Linux has VNC and NX for GUI/Desktop remote controlling a Linux system. NX is available for...
This tutorial explains how to use extended Access Control Lists (ACLs) to control access to files and directories. Standard ACLs allow the system administrator to control who can access files and directories but they have limitations. For example, with standard ACLs, only one user can have specific access permissions set. But with extended ACLs,...
This tutorial explains how to use permissions on files and directories to maintain good file level security as well as provide proper user access controls. Standard and Extended ACLs Ubuntu Linux allows the use extended ACLs (Access Control Lists) as well as the standard (POSIX) ACLs. Extended ACLs are comparable to Windows ACLs which...
This HowTo explains how to move an Mdadm RAID set from one server to another. For the sake of setting the scene, the old server is gone (perhaps broken or decomissioned) and we still have the disks that make up the RAID set. First we need to create the device: cd /dev MAKEDEV md...
This HowTo explains how to rate limit incoming ICMP packets. Here are the two key lines: iptables -I INPUT -p icmp --icmp-type echo-request -m recent --set iptables -I INPUT -p icmp --icmp-type echo-request -m recent --update --seconds 10 --hitcount 5 -j DROP As you can see, the above will limit incoming ICMP packets to...
This HowTo gives an example on how to use Apache2 to reverse proxy for a website. The website being reverse proxy’d works with images and CSS using this example. It’s a common error result that images and CSS don’t work. In this example, we’re setting up a reverse proxy that will reside in a...
On Ubutnu, wireless networks can be configured either through a GUI or via configuration files. Use one or the other. Otherwise you will find they compete. This HowTo explains the alter. Note that you’ll be given a dynamic IP address. apt-get install wireless-tools Edit the file “/etc/network/interfaces” to include the following. Note that AGIX...
This HowTo demonstrates how to configure Fetchmail for Ubuntu. Fetchmail is a program that will collect email from a remote email server and deliver it to the local mail system. For example, email sent to a remote email account of “andrew@remote.com” can be collected and inserted into “andrew@mymain.com”. First, install Fetchmail: apt-get install fetchmail...
AGIX has released the new “AGIX Ping” website. You can monitor your servers and receive notifications of outages via email. You can monitor your clients servers, your servers, router or anything you can connect to on typical TCP ports. http://www.agix.com.au/ping It’s free to sign up. You can monitor up to 20 servers. This is...
This HowTo explains how to configure Apache to serve files over the WebDav protocol. You should start with a working Apache2 configuration as documented here. Add the following to your “default” site. On our test system, the file is located at “/etc/apache2/sites-enabled/000-default”: <Directory /var/www/webdav> Options Indexes MultiViews AllowOverride None Order allow,deny allow from all...
Small businesses can enjoy technology usually reserved for the corporates. You’re business can look impressive by spending under $35 per month for online-FAX services, Website and Email, Online Invoicing and VoIP Telephones. Here’s how: Online-FAX Service from $9.95 Per Month Some of us still need to receive or send Faxes. But it hardly seems...
This HowTo explains a few processes to try for testing suspicions of disk errors or performance issues. The idea is to try the same test multiple times to find consistencies. Doing so may help you identify that the evenings are different to mornings or that reads are slower than writes or that the source...
FreeKar.com is the newest website from AGIX. FreeKar is about sharing local driving experiences and conditions with your community. In turn, you can avoid hazards when ‘you’ travel. FreeKar is designed to work on both smart-phones (iPhone, Androids) as well as normal computer browsers. FreeKar is completely free to use. Visit FreeKar here: http://www.freekar.com/...
AGIX has teamed with the William Light Institute to build the highest quality computer training academy in Adelaide. The academy has great facility resources and expert trainers. Pricing discounts apply for students. Larger discounts apply to students of William Light Institute. Corporate clients have discounts when booking seats in larger number. The courses range...
AGIX is happy to announce a new book that has recently been published on Amazon. The book titled “Effective Spam Prevention” is for sale on the Kindle for $9.99. It features high level anti-spam techniques for administrators. It was originally written by Andrew Galdes as a white paper for discussion but recently converted into...
The team at AGIX are proud to launch the new “Flow Internet Policy Server” range and website this week. We’re excited about this new technology. Far superior to nearest competitors, no learning curve and high performance and accuracy on both email and web content. All in one very nice device. The ability to easily...
This article explains how to configure “sudo” on Ubuntu. First, install sudo: apt-get install sudo Create your user accounts that should have access to sudo commands, if they don’t already exist: useradd -m myadmin Now run “visudo” as the root user: visudo This will give you a “vi” interface to the sudoers file. Go...
This article explains how to block someone from uploading files to a website such as Gmail or Hotmail using Squid with a simple shell script. The key feature of this process is that because we’re using an ACL, we can apply this rule to groups of users and computers as we would any other...
This article explains how to configure Postfix as your email proxy server. This is useful when you have a Microsoft Exchange server inside your computer network and you want to filter-out viruses and spam before your Exchange server receives the email. The Postfix server is the middle-man. Consider reading about virus scanning incoming emails....
This article explains how to retrieve email addresses of users from Active Directory using the Linux command “ldapsearch”. Install the required tools: apt-get install ldap-utils The following command will report all email addresses from a specific organizational unit in Active Directory. Here are the AD details: 1. Username to authorize our query (bind’ing) =...
This article explains how to block websites mentioning certain key words. This can be dangerous so we have to be careful. By dangerous i mean, we have a high likelihood of accidentally blocking fine websites. You should configure a working squid server and install squidGuard using this HowTo. Now we modify the squidGuard configuration...
This article explains how to restrict access to your web server (Apache2) by usernames and passwords. Install apache: apt-get install apache2 Edit the file “/etc/apache2/sites-enabled/default”. Add the following section. In this example, we are restricting access to the “lightsquid” directory which is accessible from a web browser at “http://www.agix.in/lightsquid”. <Directory /var/www/lightsquid/> DirectoryIndex index.pl index.cgi...
This article demonstrates how to restrict “some” users from sending emails at specific times of the day. For example, you can limit some users to only sending emails in their lunch break – while allowing other users to send emails at any time they choose. Postfix doesn’t have internal capacity to limit access by...
This article demonstrates how to configure squid authentication against Active Directory. Start by installing the components: apt-get install samba samba-common squid krb5-user krb5-clients Configure kerberos. During installation above, you were asked for the domain name and password servers, etc. We’re going to reconfigure Kerberos in this step removing those previous settings. Change your “/etc/krb5.conf”...
This HowTo demonstrates the use of LightSquid, a tool to generate a report on user (employee) web surfing habits. It will show downlaods per user, time per user and website statistics. Very useful. You can see a sample here. You will need a working Squid proxy, Apache server and Perl installed on the system...
This article described how to set “time of day” restrictions on your squid proxy, thereby regulating when web-surfing access is permitted. Make sure to backup your configuration files before making changes. This is a complete squid configuration file that will prevent staff from surfing the web during business hours. Surfing is permitted during lunch...
This article demonstrates how to test if a service (program) honors the TCP wrappers security files; “/etc/hosts.allow” and “/etc/hosts.deny”. You may also like to read more about hosts.allow and host.deny security. The command example is: ldd /path/to/service | grep libwrap For example, to test if SSHd is honoring the TCP wrappers: ldd /usr/sbin/sshd |...
This article discusses how a small business can protect their computer systems from disaster. Most disasters for SME’s are related to loss of data and computer down-time. Both of which can be prevented (or at least minimized) by following this checklist. Step 1. Make sure every computer in your business is running current anti-virus...
This HowTo will demonstrate how you can run a program on one computer but have it display on another. For this example we’ll assume you have a server with an IP address of “192.168.0.1″ and a desktop computer with an IP address of “192.168.0.2″. You want to run an application on the server but...
Zimbra is a Microsoft Exchange alternative. It has shared calendars, contacts, todo lists and more. Best of all (for Windows folks) it work with Microsoft Outlook (all versions that I’m aware of). Zimbra comes with it’s own Web Interface (improvement on OWA) and a portable interface called “Zimbra Desktop”. Zimbra Desktop has off-line mode,...
This HowTo demonstrates how to install and configure Tripwire. Tripwire is a tool that checks your system files for changes. Any changes are reported to the administrator. Ideally you would place the tripwire database in a read-only location such as an NFS mount or floppy disk to protect its integrity. In the interest of...
This HowTo demonstrates how to fail a disk within an MD RAID set, how to remove it and how to add in a new disk to replace the faulty one. This tutorial continues on from an earlier HowTo article. You may want to visit and review that article first. Given that this is a...
This HowTo goes through the process of formatting a partition (could be a partition on a RAID set or perhaps a single disk) with LVM2 and then formatting the LVM2 partition with EXT3. This tutorial is simplified and uses one LVM2 partition on a single disk. However, the real power of LVM2 is that...
This tutorial will walk you through creating a software raid set. As this is a tutorial, we’ll use loopback devices as hard disk – which means you can do this tutorial without needing to purchase new hard disks. If you are using physical hard disks, this tutorial will be fine. Just skip the part...
For this article to be of any help to you, consider our testing environment. We have a an ESXi 4.0 server accessing VM’s stored on the NFS NAS server. This article has a focus on the NFS tuning side of things, not LAN, VM or Linux file system and RAID configuration. All of which...
This HowTo shows how you can analyze your email log files on Linux. The output is emailed to you. The email address you enter into the myEmail variable (near the top of the script) will be used to determine your domain of interest. Create your script file: touch /usr/bin/mailcheck.sh chmod 755 /usr/bin/mailcheck.sh Now add...
This HowTo explains the process of configuring Postfix to scan emails for virus infected content. This HowTo requires that you have a working Postfix installation to start with. You can read other articles on this site for more Postfix tutorials. You may be interested in this mail analisys script. It will email you a...
This HowTo explains the use of a backup email server using Postfix. A backup email server is also sometimes known as a backup MX. When an email is sent to an email server, the sending email server will lookup the “MX” DNS record for the destination domain to find out which server should receive...
