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.

Upgrade PHP for CentOS 6 Using Additional Repositories

PHP 5.3 to 5.6 Upgrade for CentOS Using External Repos

CentOS Linux is often an option when configuring a Virtual Private Server (VPS). CentOS is designed for stability, being based upon Red Hat Enterprise Linux (RHEL). This means that although it has a long shelf life it may not have the latest features available to the Linux community. To help overcome this other repositories can be used to update the CentOS installation. Here is a list of some alternative repos for CentOS that provided various updated packages:

CentOS PHP UpgradeOne package that may require updating is PHP. CentOS 6 will be supported until 2020 but comes with PHP 5.3, a few point releases behind the current PHP version. In this article the PHP available in CentOS 6 is updated to a later version. This tutorial is based upon a VPS running a minimal installation of the latest version of CentOS 6, the 64 bit version. The tutorial was tested on a Virtual Machine (VM) duplicate of the VPS on a local machine to ensure that the configuration steps correctly worked before applying the upgrade to live environment. Always have a backup of live data and always test upgrades on a duplicate test system. This minimises the risk to a live system.

It is assumed that the VPS is accessed via a Secure Shell (SSH). This method of access can be duplicated on a local test environment to replicate the real world set up. To upgrade PHP log in to the VPS and install an alternative repo, then use yum to install the later PHP version. Here repositories from Les RPM de Remi is used. 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

CentOS 6 to CentOS 7 Upgrade Using Red Hat Upgrade Tool

CentOS 7 Supports In-Place Upgrading from CentOS 6.x for 64-bit Versions

This article covers upgrading a minimal CentOS 6.x system to CentOS 7. CentOS is a popular GNU/Linux OS for servers (including web servers) and workstations. Popular because it is a community based version of RHEL. CentOS is often an OS option when purchasing and setting up a VPS. The current major version of CentOS is version 7. CentOS 7 can be installed via an in-place upgrade over CentOS 6. However, CentOS 7 is only a 64-bit OS and therefore the system being upgraded has to be running 64-bit CentOS 6. To check if CentOS is 64-bit or 32-bit use the uname command with the -p option (p for processor):

[root@servername ~]# uname -p
x86_64

The 64-bit CentOS will display x86_64 and 32-bit will display i686.

CentOS 6 to CentOS 7 UpgradeWords of caution. If your system has been highly customised then performing an in-place upgrade from CentOS 6 to 7 may not be successful. In this case, as for upgrading a 32-bit system, a data backup, new CentOS 7 installation and data restore will be required. Do you need CentOS 7 now? There is also no need to rush to upgrade to CentOS 7. CentOS 6 will be receiving updates until the end of 2020. This article is for informational and test purposes only. You are responsible for you own actions and an in-place upgrade from CentOS 6 to CentOS 7 is probably more trouble than doing a fresh CentOS 7 install and data restore. For example upgrading a minimal CentOS 6.6. to CentOS 7 may not work according to this bug report.

The other consideration is whether the new CentOS 7 features will hinder operation of your system. The new features may require changes to the normal workflow or they may be incompatible with software that is being used on the system. Whilst the CentOS 7 Release Notes list some major changes the RHEL 7 Release Notes has a detailed discussion. Continue reading

hiberfil.sys Windows 8.1 Delete to Free Up SSD Space

Disable Hibernation on Windows 8.1 to Remove hiberfil.sys for More Disk Space

This article provides a tutorial on removing the Windows hibernation file to free up disk space when a small solid state disk (SSD) is used as the system drive. Please ensure you have a backup of any data and files you need to keep before changing system configurations. This article is for information only. System configurations can vary widely, therefore any changes made are at your own risk. If you’re confident with computers and understand the meaning of the hiberfil.sys file you can skip to the end of the article for the relevant command, which is to run powercfg -h off at the administrator’s command prompt, otherwise read on for a better understanding.

Background

Low Disk Space on a Windows SSDApart from low end systems a SSD drive is standard fitting to most computers and laptops. An SSD is also a common upgrade to older systems. A SSD is more expensive than a hard disk drive, as a result small capacity SSDs (less than 128 GB) may be used to keep costs down. Windows 8.1 requires 20GB for installation, modern computing demands soon eats into the the remaining space. A system can be configured to use a small SSD for the Windows system and a large multi-terabyte  hard drive for data storage (see Move My Documents and Other Personal Folders). Despite this, or if a second drive is not an option, the SSD may fill up quickly with normal use. Once the SSD is full the computer or laptop will not function properly, may not boot up, or show error messages at boot time. The worst case scenario is data corruption and loss, or even disk failure, when applications cannot handle running with no disk space available. Continue reading

Thunderbird Change Password for Email Account

Update or Change Password in Thunderbird to Access an Email Account

Occasionally it is required to change the password used to access email on the email server. If using an email client, for example Outlook or the free Mozilla Thunderbird app, the email password stored for the account will require updating. In Thunderbird the password is not stored under Account Settings but is stored under Security in Options. For Thunderbird change password is achieved by removing the stored password so that a prompt appears to enter the new password. This article explains the problem and how it is fixed.

Thunderbird LogoWhen a email account is added to Thunderbird the Mail Account Setup dialog has a box that allows the entry of the password for the account. A check box is used to ensure that the password is remembered (so it is not typed in each time Thunderbird is opened).

The settings for an email account in Thunderbird can be accessed in several ways, see the following list, however these settings do not give access to the password field:

  • Bring up the context menu (usually right-click in Windows) on the account name, in the folder view, and selecting Settings.
  • Select View settings for this account when the account is selected in folder view.
  • Use the menu button next to the search box and select Options and then Account Settings.

If the email account password has changed Thunderbird will not be able to login to receive and send emails. Hopefully the option to renter a new password will be given: Continue reading

Visualization for Cyber Security Conference List of Papers

All Papers from the Annual Visualization For Cyber Security Symposium

Whilst researching novel methods for visualising data from computer security systems the VizSec conference proceedings looked interesting. VizSec is short for Visualization for Cyber Security. This is an annual symposium dedicated to the use of visualisation techniques to help with the complexity of monitoring the large modern systems we all use. System security has become a big data problem and only efficient data analytics will help manage it.

The 11th International Symposium on Visualization for Cyber Security takes place in November 2014. The papers from the previous 10 years of symposiums are available from different institutional or publisher web sites. This means there is not a single search available to get one list of all the papers presented at VizSec over the years. Therefore visits to several web pages and web sites are required to put together the list of all papers presented at VizSec. Since this has now been done that list is published here. Therefore you don’t need to repeat the work. Continue reading

BBC Website Down with BBC Home Page and iPlayer Offline

Highly Ranked BBC Website Experiences Period of Down Time

On Saturday 19th July 2014 the BBC website, http://www.bbc.co.uk, went down. Although no web site can be 100% reliable the length of the BBC website down time was unusual. The iPlayer service was offline as well. The down time issues stretched into the Sunday 20th July, with the BBC Home Page experiencing the longest outage, continuing into Monday 21st July. Initially a generic “Error 500” server page was displayed stating:

We are experiencing abnormal traffic to our network or the service or servers it is on is not currently available.

This was later replaced by a BBC home page of a much simpler design than the normal one:

Due to technical problems, we are displaying a simplified version of the BBC Homepage. We are working to restore normal service.

BBC Website Down

People accessing the BBC iPlayer service saw a message:

BBC iPlayer temporarily unavailable due to a technical problem

BBC iPlayer Down

Reports to Downdetector for iPlayer showed iPlayer outages over that weekend. BBC News reported the problems. The @AboutTheBBC Twitter account posted regular Tweets:

bbc_website_down_reported_on_twitter

Some of these were retweeted by @bbccouk and @BBCiPlayer.

BBC Website is in Top 100 of All Websites

According to Amazon’s Internet analytics company Alexa the BBC is ranked in the top 100 of all websites and is in the top 10 for the UK. A long term outage of a top ranking website is not unheard of but is uncommon enough to be news worthy. Whether it is caused by a distributed denial of service (DDOS) or another issue is unknown. Although DDOS is unlikely as apparently the BBC has a 700 Gbps connection. Furthermore a DDOS is usually mitigated within a few hours, thus it is likely to have been a technical fault or failure in updated software. Although that is just speculation and the TechAdvisor website reported that the servers had a ‘severe load’.

Two years ago lengthy BBC website down time issues were also reported in the UK press.

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