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Data Recovery and the Three Golden Backups

Our daily lives are tied to the digital world. Where once we had physical photos, CDs, books and files we now generate and buy the virtual equivalents. We store them on our electronic devices and assume that they will last forever in their digital homes, never needing to use data recovery to restore our virtual assets. But do they last forever?

Data Recovery when Computers Breakdown

A home computer can at any time be holding years of personal information and photos. Items that are irreplaceable to you. How long have you had your computer? The older a machine the greater the chance it will breakdown. When it does break you can feel you have lost part of who you are, this can be a scary time especially if you don’t have a backup. Try and stay calm and read this article from Cheeky Munkey about how to recover data from the hard drive within your computer.

data recovery needed

Avoid Hard Drive Data Recovery with Backups

Never get to the point where you need to recover lost files. Most companies that deal with data will have multiple copies of it. Three copies of any file is considered the minimum required. Just as the hip-hop group De La Soul thought that three was The Magic Number you can also use three as the magic number to prevent the need for data recovery.

  1. The original.
  2. A local copy on transportable media (e.g. USB drive, external hard drive).
  3. An off site copy (e.g. cloud storage or on media stored elsewhere, such as a family members house).

Backups are your files insurance policy for when your computer breaks down or is lost. The Internet has made preserving copies of files easier with services like Apple’s iCloud, Microsoft’s OneDrive, Google Drive and Dropbox where saving to a local folder automatically generates a remote copy. But don’t forget your own local copy on portable media. Ultimately the Internet is run by businesses and businesses have been known to shut off services. So remember your three golden backups for all your content.

Responsive Menu Tutorial for HTML Web Pages, No JQuery

HTML Menu Bar Which Switches to Dropdown for Mobile

For a web site to be successful it must tick several boxes. It needs an attractive design, great content, no pop-ups, not throw to many advertisements at visitors and work well on a variety of screen sizes. The last point is important as mobile devices are now the dominant platform for accessing the web. Achieving multi-screen support from a single web site saves time (no need to update the design more than once). Time is a precious resource for most people and businesses.

A web site needs to respond to the device it is being viewed on, hence the term responsive design. When a website uses a menu to allow the viewer to jump to other pages, that menu should work well on different screen sizes. This article is a responsive menu tutorial giving an example implementation of the Responsive Nav plugin. This provides a basic responsive web site menu without using any other frameworks or libraries. As the screen shrinks the menu switches from traditional horizontal to a button. The button is used to dropdown the menu on smaller screens. Continue reading

Show PHP Settings with phpinfo and Example PHP $_SERVER Display Page

View PHP Environment Configuration Settings and Superglobals on a Page

PHP is a great computer and web site scripting language and extremely popular. It is used primarily for developing interactive web sites and many use it for day-to-day programming tasks. There are several versions in general use and sometimes the configuration of PHP between servers and machines needs to be compared. The phpinfo() function is a one line solution to show the current live PHP set up. To show PHP settings simply create a one line PHP web file on the server containing <?php phpinfo(); ?> and point the browser at it. HTML tags are NOT required because the phpinfo() function pumps them out.

PHP LogoNote: phpinfo() outputs a lot of useful information, information that hackers find interesting so use it with care. Ideally do not have the phpinfo() page on a public facing web site. On the occasions you do take precautions to reduce information leakage. Put the page in a password protected directory, do not call it phpinfo.php as this is obvious to hackers (use something more obscure and a reminder to delete it when finished, e.g. quick-config-check.php), finally don’t forget to delete it when the PHP settings have been checked.

A PHP script will need access to other settings that PHP provides, often via system wide globals known as the superglobals. The $_SERVER array provides access to the _SERVER superglobal and is shown by phpinfo() in a table. Occasionally it can be worthwhile viewing such values from another PHP file. This can be done in a few lines of code. The following provides some details on showing PHP settings and global values in web pages.

Continue reading

Unzip File on VPS? How to Extract a Zip File on a Linux VPS

Tutorial to Upload and Extract a Zip File from Windows to a CentOS VPS

On Linux files are normally compressed individually to create a .gzip version using the gzip utility. Or several files are collected into a Tape Archive, .tar, which is an uncompressed collection of files created using the tar utility. A .tar is then compressed to a .gzip to create a .tar.gz. In Windows files are normally zipped, which is a format that collects and compresses several files into a single .zip file in a single operation.

When managing a Linux based Virtual Private Server (VPS) or other remote Linux machine, such as a web server, there can be occasions when a zip file created on Windows needs to be extracted and managed on the remote Linux machine. This can be done with the Linux zip (to compress) and unzip (to extract) utilities.

Install Zip and Unzip onto CentOS

Upload and unzip file on VPS (CentOS)A VPS may not run a full blown Linux, for example a CentOS VPS may run the minimal CentOS installation for efficiency. In which case the zip and unzip utilities may not be installed. These utilities can be installed on CentOS using yum:

Continue reading

WebMatrix Rename Site and Changing Virtual Folder Name

Renaming Websites and Folders in WebMatrix

Using a free package it is possible to develop a website on Windows using Microsoft WebMatrix. This program allows you to run a website on your local Windows computer. When a website is created in WebMatrix it will usually have the name EmptySiteX where X is a number. The name is the same as the folder in which the website files are stored. Where does WebMatrix create this folder? This folder is normally in My Web Sites in the logged on user’s Documents folder:

C:\Users\John Doe\Documents\My Web Sites\EmptySite1

(Tip: Using the WebMatrix settings this default location can be changed.)

Changing a website name in WebMatrix is easy. Open the website in WebMatrix with the Home tab selected. Ensure site folder is visible (select Files or the files icon on the left hand panel to see everything that makes up the site). Bring up the context menu (usually right-click) on the top level folder. Select Rename and enter the new name:

WebMatrix Rename Site

A brief status message is displayed at the bottom of WebMatrix. Then to completed the WebMatrix rename site an edit of the IIS Express applicationhost.config file is required. Continue reading

PHP on Windows Using WebMatrix Single Click Install

Running PHP to Test Websites on Windows PCs

PHP is a programming language that is popular for for adding powerful features to websites. What does PHP mean? PHP originally stood for Personal Home Page (after its inventor, Rasmus Lerdorf, wanted more features for his personal website), but now it stands for PHP Hypertext Preprocessor (creating a recursive acronym, which programmers like). PHP is easy to set-up and run on a Windows PC using the free Microsoft WebMatrix, an Integrated Development Environment (IDE) for building websites.

With the free WebMatrix package PHP on Windows is a single click install and allows website testing using IIS Express (the version of Microsoft Internet Information Server for Windows clients). This tutorial assumes that WebMatrix is installed and running on your Windows 7 or higher PC. If not see our article Develop a Website on Windows Using Microsoft WebMatrix to set it up and get a basic website going. Continue reading

Develop a Website on Windows Using Microsoft WebMatrix

Create a Free Website Online Using WebMatrix, Azure and Microsoft Windows

If you have a Windows laptop or desktop computer you can get started with website development with free Microsoft tools. One of several free software tools that Microsoft provides is WebMatrix. This contains a HTML editor in an Integrated Development Environment (IDE) and the express version of Internet Information Server (IIS) (a web server used for testing your website).  A Windows PC running WebMatrix allows you to develop a website and publish it online for free using Microsoft Azure cloud hosting. Microsoft free hosting is for a small number of low volume websites. If the website is successful and generates high traffic it can be upgraded to a registered domain and paid for high volume Azure hosting.

This tutorial was based upon using a Windows 8.1 PC but Windows 7 can run WebMatrix. You will need an Internet connection and a Microsoft account to install and run WebMatrix and to use Microsoft Azure. Continue reading

Webmin CentOS Install for Easier VPS Management

Manage a CentOS VPS Using Webmin for System Administration

A Virtual Private Server (VPS) is a cost effective way to host web and cloud based solutions or high volume web sites. A VPS provides more resources (memory, processing power and disk space) than shared hosting without the cost of leasing dedicated hardware (although a VPS will not be as powerful as a dedicated machine). Some VPS packages only provide a minimal Linux system. Access to that minimal system is usually via a secure shell (SSH). Managing a Linux system remotely over SSH can be cumbersome. To make the system administration easier a web based management tool is useful. A commercial tool such as cPanel is often provided at extra cost. Open source alternatives like ZPanel and Webmin are available. In this tutorial article the Webmin system administration tool will be installed on a CentOS based VPS. CentOS, based on a Red Hat Linux distribution, is commonly available for VPS packages. This article assumes that the minimal installation of CentOS is used for the VPS operating system. The minimal CentOS does not have the desktop environment installed. The steps for the Webmin CentOS install are:

  1. Update CentOS using yum update.
  2. Add Webmin to the CentOS yum repositories.
  3. Add the Webmin package PGP key to the RPM keyring.
  4. Allow Webmin through the CentOS iptables firewall.
  5. Install Webmin using yum install webmin.
  6. Start Webmin and start using it.

Webmin Install Running on CentOS Continue reading

Change SSH Port from Default for CentOS Security Improvement

Help Harden a CentOS Server, Change SSH Port from Default Port Number 22

Edit the SSH configuration file to modify SSH port number. The configuration file is sshd_config. Adding Port XXXX where XXXX is the required port number. Then update SELinux and iptables. This is done to help harden CentOS against the less skilled hackers. The Secure Shell (SSH) is used to access a CentOS Server from another computer. For example when accessing a Virtual Private Server (VPS) to perform configuration changes. CentOS is a common option for a VPS operating system. This tutorial provides details on changing the SSH default port number for a CentOS server.

Steps to Change the CentOS SSH Port Number

The following steps are performed to change default SSH port number on CentOS:

  1. Login to the CentOS server.
  2. Back up then edit the /etc/ssh/sshd_config file.
  3. Add the line Port XXXX to the file, where XXXX is the new port number.
  4. Update the SELinux policy for the new SSH port.
  5. Update the iptables firewall rule for the new SSH port.
  6. Restart the services or the server.
  7. Check the changes worked by connecting on the new port.

Practice and Keep A Back Up

CentOS Logo

It is recommended to practice the instructions that follow on a local test environment before doing it on a live machine. This ensures familiarity with the process and reduces the risk of making mistakes on a live server. CentOS can be configured on a local Virtual Machine (VM) to practice these changes (see the Further Information section at the end of the article). For a remote VPS if you make a mistake reconfiguring the SSH port you may not be able to connect to it. It will require resetting via your service provider’s control panel. Always ensure you have a backup of any data that needs to be kept in the event the VPS needs to be reset. If SSH is the only option for configuration of a remote VPS consider other hardening options first, for example adding a sudo user for SSH login and removing the root user login over SSH. This article uses the shell (command line terminal) to change the CentOS configuration, based on a minimal CentOS install.

Edit the File sshd_config

To change the SSH port number edit the /etc/ssh/sshd_config file. Start by taking a copy in case anything goes wrong. For all commands in this article only enter the text after the # or $ prompt character, as seen on the terminal screen. Here’s the command to copy sshd_config to sshd_cfg_old:

# cp /etc/ssh/sshd_config /etc/ssh/sshd_cfg_old

Editing is done with vi or nano. On a minimal CentOS install, typical for a VPS, nano will not be installed by default. To edit sshd_config using vi:

# vi /etc/ssh/sshd_config

Or if logged in as a user with sudo ability:

$ sudo vi /etc/ssh/sshd_config

Add the Required Port Number

Select a new port number above 1024, one that is meaningful to you so it is remembered, or pick a random one. See List of TCP and UDP Port Numbers on Wikipedia. Some admins just double up port numbers, e.g. 22 becomes 2222, but that is familiar to hackers so pick something else, e.g. pick a memorable year and double it. For example 2×1066 is 2132, so port 2132 can be remembered as “Twice Battle of Hastings“.

The Port line should be in the first page of the file, as either Port 22 or commented out as #Port 22. Go to the line. Press Insert to enter edit mode. Remove the # if present and change the port number to the required value. Press the Esc key to return to command mode and enter :wq to write out the file and quit vi.

ssh_port_config

Update SELinux with the New Port Number

If the Security Enhanced Linux module (SELinux) is running then update selinux with the new port number. Failure to update SELinux for the new port will result in a Permission denied showing in the SELinux log.  To check that selinux is enabled run sestatus:

# sestatus
SELinux status: enabled
SELinuxfs mount: /selinux
Current mode: enforcing
Mode from config file: enforcing
Policy version: 24
Policy from config file: targeted

Use semanage to add the new port number to SELinux, see the article RHEL 6: semanage SELinux Command Not Found on how to install the command if not present (e.g. if using the CentOS minimal install). For this article this command was used to check the package for semanage:

# yum provides /usr/sbin/semange

And this command to install it:

# yum -y install policycoreutils-python

The port numbers for SELinux can be displayed using a semanage command (pipe to less to page through the list):

# semanage port -l | less

In the list of ports will be found ssh_port tcp 22. Use semanage to add the new port number:

# semanage port -a -t ssh_port_t -p tcp 2132

Update Firewall Rules for the New Port Number

The iptables firewall rules are listed using:

#iptables -L

There will be a rule showing that SSH is only allowed on port 22. This needs changing to the new port number. Use vi to open /etc/sysconfig/iptables:

# vi /etc/sysconfig/iptables

Go to this line:

-A INPUT -p tcp -m state –state NEW -m tcp –dport 22 -j ACCEPT

Change 22 after –dport to the new port number, e.g. 2132 (press Insert to enter edit mode in vi):

-A INPUT -p tcp -m state –state NEW -m tcp –dport 2132 -j ACCEPT

Save and exit (Esc key then :wq). Restart iptables:

# service iptables restart

Restart SSH

With the SSH config file changed, SELinux updated and iptables rules updated SSH can be restarted:

# /etc/init.d/sshd restart

Restarting CentOS

As an alternative to restarting iptables and ssh restart the the CentOS server:

# reboot

or

# shutdown -r now

Login to CentOS Using SSH to Test The New Port

On a Windows system a program such as PuTTY can be used to access a CentOS server using SSH. In this example the port number is 2132. To connect with the new port number enter it in the Port box.

PuTTY to SSH into different port

With the host name or IP address also entered select Open. The terminal prompt should appear allowing for a normal login.

(Note: If accessing a CentOS VPS on a VirtualBox virtual machine on the local computer you will need to change the Network Address Translation port from 22 to the new number, see the third article listed below.)

Further Information