Is an external hard drive a good backup?

Backing up your data is one of the most important things you can do to protect your files. External hard drives are a popular option for backups thanks to their portability, capacity, and ease of use. But are they the right choice for your needs? Here’s a look at the pros and cons of using an external drive for backups.

The Benefits of External Hard Drives for Backup


One of the best things about external hard drives is that they are portable. You can easily unplug an external drive from one computer and plug it into another. This makes it easy to store your backup in multiple locations, which helps protect your data in case of theft, fire, or other disaster at one site.

Many external drives are also quite small, some about the size of a smartphone. This means they can easily fit in a backpack or desk drawer for trips across town or to a different state. The portability of external HDDs allows you to keep your backup in varied places for better safety.


External hard drives offer large backup capacity for the money. While online backup services often limit how much data you can back up or charge premium rates past a few gigabytes, external drives are usually only limited by your budget.

For around $100, you can get an external HDD with 4TB of storage. That’s enough space to hold years of documents, photos, videos, and other important files. Larger 8TB+ external drives are also available if you need even more backup capacity.

The ample space external HDDs provide makes them a flexible solution for most people’s backup needs. Whether you just need to cover your most important files or create a complete clone of your computer’s hard drive, external storage has enough room.


Setting up and using an external hard drive for backup is very straightforward. Most external HDDs just need to be plugged into your computer via USB, and they are ready to use. The drive should then appear as available storage space in your operating system.

From there, you can use your computer’s built-in backup utilities or third-party software to schedule regular backups to the external drive. Many backup programs, like Apple’s Time Machine, work seamlessly with external storage devices. This simplicity makes external hard drives one of the most hassle-free backup options.


External hard drives use the same drive mechanisms as internal HDDs, so they are typically just as reliable. Consumer external drives designed for backup come with rugged casings to protect the drive inside from bumps or drops.

Solid-state external drives with no moving parts are even more durable and resistant to shock and vibration. As long as you take reasonable care of your external HDD, it should provide you with years of trouble-free performance.

The dependability of external hard drives makes them well-suited for your important backups. You don’t have to worry about technical issues or glitches preventing your backups from completing.

Potential Downsides of External Hard Drives for Backup

Hardware Failure

Like any storage device, external hard drives are still vulnerable to hardware failure. While infrequent, problems like the drive motor breaking down or the electronic components malfunctioning can make your backup inaccessible.

Drive failures may occur spontaneously or get progressively worse with warning signs like strange noises or slow performance. To limit your risk, look for external drives with long warranties of 3 years or more. Check user reviews to see if any models have higher than average failure rates as well.

You can further reduce the disruption of a hardware failure by regularly backing up an external drive to a second external drive or the cloud. This provides an additional layer of redundancy for your most critical data.

Security Vulnerabilities

Because external hard drives are portable, they can be lost, stolen, or accessed by unauthorized people if left unsecured. If someone can physically access your drive, they may be able to view your files or even install malware.

To keep your backup protected, keep the physical drive in a safe place when not in use. Also use drive encryption features like BitLocker on Windows or FileVault on Mac to password protect the entire external drive. This renders the data inaccessible even if the drive itself goes missing.

However, encryption adds complexity and makes accessing your backup from other computers more difficult. You will need to bring the password with you or store it separately.

Inflexible Storage

Once an external hard drive reaches full capacity, you will need to either delete older backups or get an additional drive to continue backing up new data. This can get expensive and cumbersome as your backup needs continue growing over time.

Online backup services often have more flexible storage options. They allow you to pay monthly for just the storage space you need. Their capacity can also scale up limitlessly over time as your usage increases.

With external hard drive backups, you are more locked into the physical capacity of the individual drives you purchase upfront. You’ll need to plan your long-term storage needs more carefully as a result.

Limited Automation

While setting up periodic backups to an external drive is straightforward, fully automating the process has caveats. For instance, the computer hosting the drive must remain powered on and connected in order to run scheduled backups. The external drive must also be plugged in via USB.

This may limit where and for how long you can keep your drive connected. For road warriors who are frequently away from their desk, keeping a computer and external drive powered 24/7 may be impractical for automated daily backups. Online backups tend to offer more seamless automation since they run remotely over the internet.

Should You Use an External Hard Drive for Backup?

External hard drives can be an excellent choice as part of your backup strategy thanks to their versatility, ample storage, and ease of use. The ability to store physical backups offline provides an extra layer of protection from malware or ransomware attacks against online files.

However, there are some downsides to consider as well. Hardware failures, though infrequent, can disrupt access to your backups unless you have redundant external drives or cloud backups too. The physical nature of external HDDs also makes fully automating backups more challenging.

Here are some best practices to follow if you use an external hard drive for backup:

  • Keep at least 2 backups of your most important files, either on multiple external drives or one external drive plus cloud storage.
  • Enable drive encryption to secure your backup against unauthorized access if the physical drive is lost or stolen.
  • Select an external HDD with at least twice the storage capacity you need today to allow for growth.
  • Replace drives older than 3 years to minimize the chance of hardware failure.
  • Set a reminder to plug in and run your external drive backup periodically if it isn’t continuously connected.

Following these tips will help you enjoy the advantages of external hard drives for backup while minimizing the downsides and risks. Backing up to both an external drive and the cloud provides comprehensive coverage at an affordable cost.

Just remember that any single backup method, whether external drive, cloud service, tape, optical media, or others, has pros and cons. Combining multiple backup mediums is the best way to fully protect your irreplaceable data from all threats.

Frequently Asked Questions

Are external hard drives reliable for backup?

External hard drives are generally quite reliable thanks to durable casing designs and the same drive mechanisms used in internal hard drives. However, any storage device can fail unexpectedly, which is why you should have redundant backups.

How long do external hard drives last?

Most external hard drives can last between 3 and 5 years with regular use. Higher-end models may last longer, while lower-end drives tend to fail more quickly. Following the manufacturer’s suggested usage guidelines can maximize your drive’s lifespan.

Can external hard drives get viruses?

External hard drives are vulnerable to malware like viruses and ransomware if they are connected to an infected computer. Always keep your computer’s antivirus software up-to-date and use drive encryption on your external backup where possible.

What size external hard drive do I need for backup?

This depends on the amount of data you need to back up. For most users, a 4TB external HDD is sufficient to hold years’ worth of documents, photos, and other important files. If you have large collections of videos and other media, you may need a larger 8TB+ drive.

How do I backup an external hard drive?

To backup your external drive, connect a second external drive and use your operating system’s file copying tools or a third party backup program to periodically mirror the contents between the two drives. This provides redundancy if one external HDD fails.

You can also backup an external drive to cloud storage services like Google Drive, Dropbox, or iCloud. This involves periodically uploading new files from the external drive to the cloud service.

Should I encrypt my external hard drive backup?

Yes, encrypting your external backup drive is recommended to prevent unauthorized access to your data if the physical drive is lost or stolen. On Windows, you can use BitLocker. On Mac, you can use FileVault disk encryption. There are also third party encryption tools available.

Can I backup multiple PCs to one external hard drive?

It’s technically possible to use one large external hard drive to backup multiple computers by partitioning the drive or assigning different folders to each PC. However, this is not recommended as it puts all your backups in one place without redundancy. Using separate external drives for each computer is safer and simpler.

How do I automate external hard drive backup?

To automate backups to your external drive, first connect it to the computer holding your important files. Then use the operating system’s built-in backup tools like Windows Backup & Restore or Apple Time Machine to schedule regular automatic backups to the external drive.

You can schedule backups daily, weekly, or at other intervals. Some backup software allows fully hands-off backups as long as the external drive is connected.


External hard drives offer an easy, reliable way to backup your most important files. Their ample storage, simplicity of use, and ability to keep data offline provide valuable advantages. However, some limitations like hardware failure risks and more difficult automation mean external HDDs work best when paired with cloud backups online.

Following best practices for using external drives, like enabling encryption and maintaining multiple redundant backups, can help overcome potential downsides. For comprehensive protection of your irreplaceable data, an external hard drive used regularly alongside cloud backup provides a robust, cost-effective solution.