We’ve shown you the magic of live CDs more than once; we even wrote a handy live CD manual. So it should come as no surprise that we’ve already shown you Clonezilla, a live CD for cloning the entirety of your hard drive. This tool is great for cloning drives, but does not come with a GUI and includes a lot of cryptic language.

Enter Redo Backup, a user-friendly live CD that makes cloning or restoring your entire drive simple. Tell the program where you’d like your cloned drive to be and you’re pretty much set.

Backing Up, Backing Up…

Boot up Redo and you’ll see two simple buttons:

If backing up or restoring is what you have in mind, these are the buttons to press. Once you’ve established the drive you’d like to copy, you can pick a destination:

You can save your clone to another hard drive on your computer, another computer on your network or a USB drive; it’s up to you. You can restore your backup at any time by using the CD again.

But Wait, There’s More…

Redo is primarily a backup tool, but it can do more than that. Click the gear button at the bottom-right and you’ll find a small menu. Browsing reveals these tools:

You can use the Disk Utility to check on the health of your drives. The file recovery tool can help you recover deleted files, while the partition editor lets you add, remove or change the size of our partitions. The usage analyzer is a great way to visually examine what’s taking up space on your hard drive.

All these tools combine to make Redo Backup an amazing tool for working with filesystems. The disk’s accessories help a little more:

The web browser is the coolest thing, giving you access to the Internet while your computer backs up. A file manager, image viewer, terminal and text editor round things out.

Need more software? Don’t worry; you’ve got full access to the Ubuntu repositories. Check out the “Administration” menu to find Synaptic, or use the Terminal, and install the tools you need.

Download Redo Backup

Ready to get started with Redo? Download it now. Once you have the ISO file you’ll need to burn it to disk. Linux users can simply right-click the file to find the option to burn the ISO to disk. Windows users will need Infrarecorder or a similar tool.

Conclusion

If we taught you well, you will know the importance of backing up. This tool makes backing up the entirety of your hard drive simple, and for that I’m grateful.

How do you like this tool? Feel free to leave praises or complaints in the comments below, along with any questions. I’ll be around.

Because of the floodwaters, companies like Western Digital have had their supply of products drastically cut. Some analysts began to warn of potential price increases several weeks ago, but they are just now becoming a reality.

Western Digital’s Caviar Green 2TB hard drive, available through Amazon.com, has soared from a price low of $69.99 on October 15th to a price high of $149.99 on October 28th.  While some other retailers do still offer the drive for under $100, their number seems to dwindle with each passing day. Other hard drive manufacturers have been impacted as well, which means they too have increased prices.

It’s hard to say when prices will return to normal, as the flooding in Thailand is ongoing and no one knows when the floodwaters will recede. Readers in the market for a hard drive should likely hold off on the purchase and keep an eye on price tracking services and extensions.

Alternatively, this could be a good time to justify spending money on a solid state drive. The flash memory used in them is made at different facilities, so SSD pricing shouldn’t be impacted (and has not been so far). Solid state drives will remain much more expensive per gigabyte of storage than their mechanical brethren, but this turn of events does close the gap a bit.

If you know of any online places where the prices for hard drives still remains cheap, help out your fellow readers by letting them know in the comments.

Source: PC Perspective
Image Credit: This Is My Next

So you think to yourself, “Well I can go into Window‘s system settings and change it, right?” Well, yes and no. While Windows lets you change the sleep behavior of your internal hard disk, there is no guarantee that the same will be applied to something Windows identifies as a removable device. Additionally, what if you’re working on a different computer, say a friend’s or public computer, where you have no access to (or at least shouldn’t) change any of the settings. What do you do now?

About KeepAliveHD

This problem is now solved thanks to an open source developer who had a simple idea that honestly works quite well. This idea has been now realized into KeepAliveHD. It’s best explained when you have it installed and can try it out for yourself, so head over to this page, click on Downloads at the top, and choose the only option that is available. Go ahead and install it normally.

Note that if you would like to have the program placed onto your external storage device, you can choose to have the installer do so. Finally, in order for it to work correctly, it seems you need to run it using administrative privileges, but the software is currently in “alpha”, so hopefully this will be fixed by then.

Configuration

When launched, the interface is quite clean and I find it easy to use. Configuring the tool is just as simple as it looks. First you’ll add the drive that you want to “keep alive”, choose how often it should do something with the drive in order to keep it awake, and whether the action should actually be enabled or just dormant. Hit OK, and add any other drives you wish to include.

Note now that even though you have one or all drives enabled, the status will still say “DISABLED”. The “Enable writing mode” checkbox seems to be the master switch, so once you enable that little box things will start to go into motion.

More Options

Below all the included drives, you’ll see a few more options that you can use. You can have the program automatically run at startup (if it’s installed on your own system), hide in the icon tray when minimized, minimize when the close button is clicked instead of out-right quitting, and whether KeepAliveHD should stop its operations if the user is inactive for a certain amount of time.

Other Tabs

In the Drive Info tab, you’ll see some basic information about your drives, such as the drive letter, the Volume Name, the amount of total space, and whether it is a fixed or removable device. Finally, the About tab will give you a description, version, and contact information.

Conclusion

While KeepAliveHD may not be a program in high-demand, it is sure to be helpful to a number of people who need something that can do this. No matter what the setting, I’m sure there will be someone who will much appreciate what this app will do for them in a simple way. It’s great to know that there are developers who think about the little things that could make working on a computer just that much better. Personally, I’d love to see something similar like this for Linux, because it is a pain in the butt when I have Linux on an external hard drive, the drive goes to sleep, and then the system can’t even retrieve the wakeup function from the drive.

What’s your favorite “trick” program? Tell us what it does and why you need it in the comments below!

Image Credit: Shutterstock

There are plenty of drives available, but most of us only need one or two, so let’s narrow down the choices and see which are really worth your money.

Best Budget Drive: Seagate 500GB Portable External Drive

This simple, portable hard drive offers 500GB of storage for a price of about $60 at most online retailers.

Features are few. The drive is a slower 5,400 RPM model, and USB 2.0 is the only connection option. With that said, this drive is quite portable, as it weighs about 160 grams and is under .7 inches (or 18mm) thick.

You’ll receive better value for your money if you pay a bit more, but if enhanced connectivity or better drive speeds are not a concern to you, this simple option will do the job.

Best Massive Drive: Seagate GoFlex 4TB External Drive

There are many options for people who want over a terabyte of space, but most are specialty solutions that become extremely expensive. At $249.99, this 4TB option manages to offer jaw-dropping capacity without a wallet-shattering price tag.

It’s more than just a big lug of a drive, however. It offers USB 3.0 as standard, and optional FireWire or USB 2.0 adapters can be purchased if desired (though I don’t know why you’d want to downgrade to USB 2.0). It’s compatible with both Windows and Mac OS X. And as if that weren’t enough, it’s a pretty fast drive, as well.

Yes, the price tag of $249.99 may sound like a lot, but you actually receive far more capacity per dollar than you would with the budget-minded 500GB Seagate drive previously recommended.

Best Backup Drive: Clickfree C6 Portable External Drive

All external drives are excellent ways to back up data, but not all drives make it equally easy to do so. One company that’s long had a leg up on the competition in this area is Clickfree, which ships its hard drives with custom firmware and software designed to make backing data easy.

The C6 even has the ability to image an entire PC hard drive, including the operating system, which means a computer can be completely restored from this drive if anything tragic happens to it. Otherwise, the Clickfree C6 is a fairly typical portable drive. It’s thin, it’s light, and it offers USB 3.0 as its sole connectivity option.

You do pay for the convenience of this drive. The 1TB portable version is $139.99, which is a fair bit more expensive than similarly equipped drive with less impressive (or any) backup features. Also, Mac users should be warned that this drive is allergic to computers designed in California.

Best Durable Drive: ioSafe Rugged Portable (Any Size) External Drive

Most of us will never place our external hard drives under much stress. Maybe the cat will tip it over – and that’s about it. Yet external drives are appealing to some people because of their portability, and if you are indeed going to be moving your data all over the globe, in a range of conditions, you’ll want a drive that won’t go belly-up.

That drive is the ioSafe Rugged Portable. Machined out of aluminum or titanium (depending on the version), this drive is watertight, chemical resistant and encases the mechanical drive itself in a shock housing that reduces the severity of impacts. The company that built it has even shown a demonstration video in which the drive was shot with a 12-gauge shotgun and survived.

It’s available in two capacities – 500GB or 1TB. Varying “Data Recovery Services” are offered by ioSafe to retrieve your data at no charge if the drive should somehow break. Mac users will have to purchase a version specific to that operating system. They’ll probably want to but don’t have to. There are USB 3.0 and FireWire 800 versions available, both of which will also work with a USB 2.0 connection and so can be used on both Macs and PCs.

All of the ioSafe drives are expensive, but did you think for a moment that a shotgun-proof external drive would be cheap?

Conclusion

External hard drives may not receive the attention of tablets or smartphones, but there have been huge improvements in their quality over the years. Drives like the ioSafe Rugged Portable are stunningly durable, while the capacity of the Seagate GoFlex 4TB should satisfy even readers addicted to torrenting HD videos.

Do you think there’s a drive that should have been listed here? Let us know in the comments!

While there are lots of filesystems out there, we’ll be looking at the most popular two, FAT32 and NTFS.

About the Filesystems

FAT32

FAT32 used to be the default filesystem for many of the older, non-NT versions of Windows, such as Windows 95, 98, and ME. The original FAT specification was introduced in 1980, while the compatible FAT32 specification was introduced in 1996. More recently, an incompatible exFAT specification has been introduced that is meant to replace the use of the old FAT.

NTFS

Meanwhile, NTFS (or “New Technology File System”) was introduced in 1993, but has received many improvements over the years along with newer operating systems. While it is not used for removable storage (where FAT-type filesystems are prevalent), it is the best choice for hard drives because of the many features that it offers. The only reason NTFS is not used on removable storage is because it generates a lot of write operations to keep track of. Removing the storage device before those writes complete could potentially corrupt the data on the storage device.

NTFS Advantages Over FAT32

So what is it exactly that makes NTFS better? Unlike FAT32, NTFS is a journaling filesystem. The “journal” keeps track of changes before they actually happen, so in case the system crashes in the middle of a disc operation, disks with journaling filesystems are easier to recover.

NTFS also includes improved support for metadata; it uses advanced data structures to improve performance, reliability, and disk space utilization, and includes security access control lists.

NTFS is also capable of holding files larger than 4GB, and larger partitions can be created with NTFS instead of FAT32. FAT32 is relatively simple, and doesn’t do much for the user except hold files and some metadata. Any other differences between the two are highly technical and I won’t mention them here.

How to Reformat your Hard Drive

So how can you reformat a hard drive to NTFS? There are three different ways you can do this.

First, you can go into Computer/My Computer, right click on the drive you want to reformat (make sure your data is backed up somewhere else), and click on Format. Change whatever settings you would like as long as you have NTFS selected as the filesystem, and hit Format.

You can also right click on Computer/My Computer and click on Manage. Then, in the open window, click on Disk Management under Storage in the left pane, and wait for the service to load. From here, you can shrink, grow, delete, and reformat your partitions as you wish. Just remember to choose NTFS when you do.

Finally, you can use a third party software to do the partitioning. Often, you’ll need to burn them onto a CD if you don’t have it in CD form already, and boot off of it. From there you’ll have a lot of partitioning options to choose from. If you need one, let me suggest GParted‘s LiveCD.

Conclusion

Choosing the right filesystem is important not only for optimal functionality but also performance and piece of mind. With NTFS, you’re making a great choice for permanent storage devices that should let you use your computer to the fullest. In addition to the benefits of NTFS, many various operating systems including Mac OS X and Linux can work with NTFS, so why not use it?

Which filesystem do you prefer the most? Why? Let us know in the comments!

RAID Configurations

First off, it’s very difficult to describe RAID technologies as a whole, because the different configurations available to you create very different functionalities – but they all focus on either speed or reliability. Let’s break them down:

RAID 0: Striped

This configuration is all about speed. In short, data is spread across a number of disks (striped across the disks, in fact) – rather than being written to just one. This overcomes speed limitations of a single drive, so performance is theoretically multiplied by the number of disks you are using.

It’s a similar concept to having 4 cores in your CPU – instead of sequentially writing instructions to one CPU, you send different parts of it to 4 different CPUs, and get the answers back 4 times as quickly. You also get to use the combined space of all of the drives, so 2 x 1TB in a striped configuration will show as a single 2TB drive.

On the downside, you also have as many points of failure as drives you are using – if just one of those drives fails, all your data will be lost. In reality then, this configuration is rarely used. If the data isn’t so valuable though, you might want to set up a RAID0 on a home server or even a desktop machine.

RAID 1: Mirrored

This configuration is all about data integrity and is far easier to explain. In a RAID 1 setup, data is mirrored to the other drives – a full backup of everything is kept at all times, because the bits of data are simultaneously written to different drives, at the same time. Because of this, you only get the total drive space of a single drive, so 2 x 1TB drives set up to mirror each other will only give you 1TB total space.

This is perhaps the most common real world usage when two disks are available. When one dies, the data is still 100% there and ready for use, but the process of “re-building” the data array on the replacement drive can take a very long time.

RAID 0+1: Striped & Mirrored

This combines the best of both worlds by nesting RAID setups, but requires at least 4 disks. 2 sets of 2 striped disks are then set up, each set replicated to the other. RAID 1+0 also exists, but doesn’t vary enough to warrant a separate explanation – it’s a case of striping your mirrors rather than mirroring your stripes!

RAID 2 & Above: Parity Bits

With 3 disks, you can actually achieve a good performance and integrity compromise by using what is called a parity disk. To explain this, think on a scale of bits instead of whole drives.

A parity bit is simply an XOR combination on the other bits. XOR is a logic operation that evaluates to true if only ONE of the two input bits is true. See the following table, where P is the parity bit.

A B P
0 0 0
0 1 1
1 0 1
1 1 0

Now it turns out that this is very useful for error checking and repairing the data. If you were to erase the entire B column, you could rebuild it simply because you still have both the parity bit and A, and given those then there is only one possible answer for bit B.

Now, it should be easy to see that even if we had 2 x 1 terabyte drives worth of bits, we could still create a parity for every single bit and place it on a 3rd drive that’s also a terabyte in size. And that’s RAID3. With a 3 disk array, 2 are used to stripe the data, spreading it out for performance. The 3rd drive creates a parity set, and if any one of those drives dies, we can use the other 2 to recover it in full.

I won’t go into details about RAID 3, 4, 5 and 6 because they’re basically all variants on where and how parity bits are stored or derived, and precisely how much recovery can be done. If you’d like to read up on those, I’d suggest the extensive Wikipedia page on the topic.

Can I Use RAID On My Home PC? Should I?

Both OSX and Windows have the ability to create software RAID configurations, but bear in mind that this is going to increase the load on your operating system due to the additional computation required. I won’t go into setting them up here, but if you’d like to know more or see a tutorial on MakeUseOf, let me know in the comments and I’ll get straight on it.

A lot of motherboards also include a form of semi-hardware RAID – I say semi-hardware, because they generally still need a driver in your OS to be able to access the data, but this is still one step up from a purely software RAID, and you can even install the OS onto them for a small performance boost.

The final method of doing RAID is with dedicated hardware – upgrade cards that you can slot into your PC and take full control of the data side of things. These are of course the most reliable and best performing, but the price range is generally out of consumer budgets.

As for whether you should be using a RAID, it’s certainly worth playing around with for geek points. In terms of real world computing, the performance gains you can expect are often less than the trouble involved (an SSD would far outperform them anyway), or the data redundancy you gain can be easily achieved with other traditional backup methods.

Check out the other Technology Explained articles for more fascinating insights into the technologies behind computers and the Internet.

Image credits: Wikipedia user C Burnett, ShutterStock

However, we’ve been gifted with a Linux-native program that offers a simplified set of features that is, in my opinion, easier to use and more visually appealing. Even more so, it usually comes with distributions that offer GNOME as the desktop environment. What is it and what exactly does it do?

About Baobab

Baobab is often masked in distributions by the name ‘Disk Usage Analyzer” rather than Baobab, but once you open the program and click on “About“, the name will suddenly appear. The name is based off the Baobab (tree), which is apparently the first kind of tree the developers thought of when making the program because of the tree’s unique way in which its bigger branches go off into smaller and smaller branches.

Overall, the program is lightweight, is easy to use, and offers some interesting visuals.

Installation (If Necessary)

Like mentioned above, if you’re running GNOME then Baobab should already be installed. You can launch it via the terminal or Alt+F2 by typing in “baobab“, or by finding “Disk Usage Analyzer” in the menus. In case it’s not installed, there are a number of ways to install it. It isn’t likely that Baobab is in its own package, but check with your distribution first.

For example, in Ubuntu, you can install gnome-utils via Synaptic, the Ubuntu Software Center, or by the command sudo apt-get install gnome-utils.

User Interface

Buttons

Once you launch the program, you’ll see how easy it is to use. At the top, you’ll see various buttons of what you can scan. This includes your home folder (recommended), the filesystem, a custom folder, or a remote location. There is also a stop button in case a scan is taking longer than you’d like and a refresh button to start a new scan for any changes.

Folder List

On the left side, you’ll see a list of all folders scanned and some information about them, such as the percentage of space the folder uses out of the entire scanned area, the actual size, and how many items are inside that specific folder. There are also arrows to the side of each folder so you can go inside those folders and see information about anything that is inside.

Colorful Graphs

On the right side, you’ll see a visual representation of the information shown on the left side. On the graph you can hover over certain sections and see more information about what it is representing. There is a Rings Chart and a Treemap Chart, and I recommend you look at both to see which one you prefer. One doesn’t give any more information than the other, but organizes the information a bit differently.

Preferences

Finally, there aren’t many things to configure at all, considering it’s supposed to be simple to use. The only things you can configure under “Preferences” are any other optional locations whenever you choose to click on the Filesystem button.

Conclusion

Baobab is indeed very simple and gets you results that you can understand quickly.  I find the graphical charts to be very helpful and keeps it from being boring to being useful. I like to use Baobab occasionally to see if there is an excess of space being used in any of the folders in my home folder, and sometimes I use it simply to see the interesting rings it generates. Either way, it’s a good tool that could tell you some things about the files you’re storing that you didn’t know before.

Do you think Baobab is useful? What other features would you like to see added in the future? Let us know in the comments!

Image Credit: Shutterstock

Since a majority of people today own laptops and external hard drives, which get dragged around quite a bit, a realistic hard drive lifetime is probably around 3 – 5 years. This is an extremely short time to reliably store important data. In the best of cases, hard drives fail gradually, giving you the chance to react, get a copy of your data, and replace the storage device before facing a fatal failure. There are a host of signs that hint to a gradual failure of your hard drive. If you are unsure how much life is left on your hard drive, read this article to find out what signs may reveal an approaching failure.

1. Slowing Down Computer, Frequent Freezes, Blue Screen Of Death

These are very unspecific signs that can be caused by a million different things. However, regardless of what the issue behind these symptoms is, it is recommended that you immediately make a backup. If these problems occur after a fresh installations or in Windows Safe Mode, it is almost certain that it is due to bad hardware, and possibly a failing hard drive.

2. Corrupted Data

If you’re beginning to find files that fail to open and are corrupted even though they saved without errors or if files suddenly disappear, you should get worried. While again this could be due to a multitude of issues, it is also a typical sign for a gradual hard drive failure.

3. Accumulation Of Bad Sectors

Bad sectors are areas of the hard drive that do not maintain data integrity. They are automatically masked by the operating system and thus hard to identify, especially if large amounts of the disk are currently in use. If you actually run into bad sectors, however, that certainly is a bad sign.

You can run a manual disk check to identify errors that Windows has not spotted, yet. In Windows 7, go to > Start > Computer and right-click on the disk or partition you wish to check. Select > Properties, in the window that opens switch to the > Tools tab and click > Check now… In the Checking Disk window place a checkmark next to > Automatically fix file system errors and > Scan for an attempt recovery of bad sectors.

Windows will also check for bad sectors, when you perform a full format or chkdsk command. See this article - The Difference Between Windows Full Format & Quick Format [Technology Explained].

4. Strange Sounds

When you hear strange noises coming from your hard drive, it may be too late already. A repetitive sound also known as the click of death is caused by the head as it is trying to write data and recovers from errors in doing so. Grinding or screeching noises indicate that parts of the hardware, for example the bearings or spindle motor, are failing.

5. S.M.A.R.T. Data

There are tools that aim to predict hard drive failure by reading the S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) data that is recorded by the operating system. Unfortunately, like most other methods listed above, S.M.A.R.T. is notoriously unreliable in predicting hard drive failure and the catastrophe will often happen before the warning of S.M.A.R.T. kicks in. If you have a working hard drive, however, and would like to have a look at its S.M.A.R.T. data, check out this article - 4 Tools To Predict and Prevent Hard Drive Failure

I Think My Hard Drive Is Failing, What Shall I Do?

So you are worried that a hard drive failure is just around the corner? The truth is, even if you are not worried, it is! The only thing you can do is always keep backups of your data on a second hard drive. The likelihood that both drives will fail simultaneously are very rare. An exception would be natural disasters like floods or fires. For these cases, I recommend to keep a copy of your most important data in a different physical location, for example at work or with a friend, or possibly on a remote server, for example by using an online backup solution.

For more information how to back up data, read my PDF manual Stuff Happens: The Backup & Restore Guide.

Conclusion

Do not rely on signs or software to tell you whether you have a failing hard drive. It is more likely than not that it will fail unexpectedly and without any warning signs whatsoever. Rather than trying to forecast something that is even less predictable than the weather, you should rely on backups.

What is your worst hardware failure nightmare, did it ever happen to you, and did you actually lose any data?

Image credits: Anyka, malost, lucadp, Matthias Pahl

If this information made you a little nervous, let me connect the pieces for you and show you how you can terminally and permanently delete files, not only from your hard drive, but also from other re-writable storage devices.

Low Level Formatting

The kind of formatting most of us do is known as high level formatting, and whether you perform a quick format or not, your data won’t be deleted. What high level formatting does is set up the file system from scratch and in the process the information where files were stored is removed.

Low level formatting on the other hand re-initializes the disk and resets the values of each and every magnetic domain, which represents one bit, to zero. We have thoroughly covered formatting on MakeUseOf and if you would like to look into the details, I recommend the following articles:

• How To Format A New Internal Hard Drive
• The Difference Between Windows Full Format & Quick Format [Technology Explained]
• How To Completely & Securely Erase Your Hard Drive [Windows]

Darik’s Boot And Nuke

Low level formatting isn’t 100% efficient and may leave traces of data. If you wish to wipe an entire disk before you dispose of it, I recommend Darik’s Boot and Nuke, a boot disk that will automatically and completely delete data on any detected hard disk.

A walkthrough of Darik’s Boot and Nuke can be found in this article:

• How To Completely & Securely Erase Your Hard Drive [Windows]

CCleaner

If you are already using CCleaner, you should know that it contains a Drive Wiper.

Open CCleaner and go to > Tools > Drive Wiper. You can wipe only free space or the entire drive, and you can choose up to 35 passes, meaning data will be overwritten with random strings of binary code 35 times. This very complex overwrite should make it impossible for anyone to restore the data originally saved in this space. When you’re happy with your settings click > Wipe and wait patiently.

SDelete

Microsoft made it very easy to not delete files thoroughly. To make up for this potential security hole, they released a free command line utility called SDelete. This doesn’t make removing data any more convenient, but it can be considered a step in the right direction. Unfortunately it is a very small step, since Microsoft fails to provide instructions on how to properly open SDelete in the first place. Well, that’s what MakeUseOf is here for.

1. Download the ZIP archive containing the tool and extract the folder.
2. Click > [WINDOWS] + [R] to open the Run window.
3. Type > cmd and click > OK to open the command prompt.
4. Then move the > SDelete.exe file to the directory > C:\User\yourusername
5. Now type a command in the command prompt, for example > sdelete -z to cleanse free space on your C: partition. A full list of commands is shown in the screenshot below.

Eraser

Eraser is a freeware and open source security tool to completely remove data from your hard drive. It can overwrite data several times using randomized patterns of binary code. It essentially is a file shredder.

Eraser is more convenient than CCleaner’s Drive Wiper because it can delete and shred single files, rather than just wiping all free space on a drive, and it is integrated with Windows Explorer (right-click menu). Moreover, Eraser provides you with a host of advanced settings, for example different file and space erasure methods, the option to replace erased files with other files to allow plausible ‘deniability’, and schedule erasure of files, folders, recycle bin, or unused disk space.

The tool is also available as a portable app called EraserDrop Portable. It is part of the PortableApps suite.

We have covered Eraser in its (and MakeUseOf’s) very beginnings four years ago. Both have come a long way since. Feel free to check out the article here - How To securely Retrieve and Delete PC Files

Other Tools

There are several more file shredders that can securely delete files from your hard drive. Some of them were covered in the article 4 File Shredders to Make Deleted Data Unrecoverable. If you need to secure sensitive data without deleting it, you should seriously look into encryption and the article Encrypt Or Completely Wipe Files With the Axcrypt Encryption Utility [Windows] provides an excellent start.

Do you have nightmares of what someone might find on an old hard drive you discarded?

Image credits: R. MACKAY PHOTOGRAPHY, LLC

The article outlines how data is stored on the physical level, which is essential to understanding why it can not be restored after being overwritten. If you are interested in the organizational structure of a hard drive, i.e. how the storage of files is managed, please read the article What A File System Is & How You Can Find Out What Runs On Your Drives. For more information on how to recover deleted files, see the resources at the bottom of this article.

How Is Information Stored Digitally?

Digital information is stored in bytes. Each byte contains 8 bits. Each bit has a value, which is either 0 or 1. This way of storing data is called the binary numeral system as it uses two symbols, i.e. 0 and 1. Subsequently, any data stored on a computer is written in the binary code, which is a string of 0s and 1s.

How Do Hard Drives Store Information?

Information on hard disk drives (HDDs) is stored magnetically and non-volatile, meaning no power is required to maintain the stored information. Every magnet has a plus (+) and a minus (-) pole, which equals two values and thus allows it to represent the binary code. The HDD storage unit or platter contains a ferromagnetic surface, which is subdivided into small magnetic regions, called magnetic domains. HDDs store data by directional magnetization of magnetic domains. Each magnetic domain can be magnetized in one of two possible directions and subsequently represents one of two values: 0 or 1.

There are two different technologies for recording data on a HDD. Prior to 2005, the recording layer was oriented parallel to the disk surface (horizontally), meaning the binary code was represented by directional left vs. right magnetization (longitudinal recording). At around 2005 a new technology was introduced and data was written by magnetizing segments vertically, i.e. up vs. down (perpendicular recording). This allowed closer magnetic domain spacing and also enabled larger storage capacities.

How Is Data Stored In Random Access Memory (RAM)?

Essentially, data is stored the same way as on a hard drive, i.e. in binary code. The major difference is that this type of storage is volatile, meaning any stored information is lost as soon as power is removed. A RAM is made up of integrated circuits, which in turn contain capacitors and transistors. Each capacitor stores one bit of data. The state of the capacitor can either be charged or discharged, i.e. 1 or 0, representing the binary code.

What Happens When Data Is Deleted?

In a RAM module, the organizational structure is very flat. When data is removed from memory, the actual information vanishes instantly. Also, when power is lost, the capacitors quickly discharge and hence all information is lost.

The situation on a HDD is completely different as information is stored in two ways. First, data is stored physically on the magnetic hard drive. Secondly, all stored data is managed by a file system, which creates an information table revealing the exact location of data, i.e. where on the hard drive a certain file is stored. This is necessary because one file can be stored in different locations across the hard drive. The operating system then uses this table to locate files and put together the pieces of large files.

When a file is deleted, typically only the information stored in the file system’s table is removed. Since it would take too long to delete the actual file, the physical location of the data remains untouched. When the operating system wants to store new files, however, it consults the table for available space. Since the location of the deleted files was marked as vacant, the operating system may then write new data over the old data, which terminally deletes that information.

For details on how the file system works and how it organizes and manages hard drives, see my article What A File System Is & How You Can Find Out What Runs On Your Drives.

What Happens When A HDD Is Formatted?

The type of formatting that most users are familiar with is called high-level formatting and it is the process of setting up an empty file system. Since it does not require scanning the hard drive for defects, it is also called quick formatting.

Typically, data stored on the hard drive is not physically deleted during formatting. What does happen is that the file system is set up from scratch, meaning the hard drive is re-organized and the table with information where files are stored is reset. As long as the file system and its settings remain the same, none of the actual data previously stored on the hard drive is deleted or overwritten and can subsequently be recovered.

What Happens When Data Is Overwritten?

When data is overwritten, the magnetic domains on the HDD are re-magnetized. This is an irreversible process that physically removes information previously stored in this location. While some residual physical traces of the changes (or none changes) in magnetization potentially remain, which may theoretically allow a partial restore, this would require the use of a magnetic force microscope or similar technologies, none of which have been shown to recover data successfully so far [although you never know what's going on in secret government intelligence labs]. So in essence, there is no software or other technical way known to the public that can restore overwritten data.

Do you need to recover data that has not been overwritten, yet? Please check out these resources:

• How to Recover Data from a Corrupt Memory Card or USB Drive
• How to Scan a Reformatted Hard Drive to Recover Files
• 3 Remarkable File Recovery Tools
• How To Recover Deleted Files From Your Linux System
• Recover Lost & Deleted Files on Mac with Disk Drill
• How To Repair Damaged CD’s Or DVD’s & Recover Data
• How to Recover Deleted Pictures from a Digicam Memory Card
• How To Get Data Off A Dead Hard Drive

Many more great resources can be found in reply to these questions posted on MakeUseOf Answers:

• How can I recover deleted files in Windows?
• How can I recover data that were shredded in Windows?
• How can I recover data from a corrupted USB drive folder?
• How can I recover data from a broken microSD card?
• Is it possible to recover data from a broken CD?
• How can I recover data from a faulty USB external hard drive?

What are your data storage and recovery nightmares? Did you ever lose files after accidentally deleting them?

Image credits: Sergej Khakimullin, Carlos Castilla, MilanB, TylzaeL & Luca Cassioli, Colour, Zketch, Anthonycz