Having regular backups of your important data is critically important to avoid losing that data due to hardware failure, theft, accidental deletion, and other hazards. But how many backup drives do you really need? Is one backup drive enough, or should you have two or more?
Quick Answer
The quick answer is that having two backup drives is better than having just one. Here’s why:
- Redundancy – If one backup fails or becomes corrupted, you have another backup to fall back on.
- Rotating backups – You can alternate backups between the two drives to have a recent backup available if one drive fails.
- Separation – Keeping backups in two physically separate places reduces the chance of losing both to the same localized disaster like fire or theft.
- Extra capacity – Two drives doubles your total backup storage capacity.
The Case for Two Backup Drives
Let’s look in more detail at the advantages of having two backup drives compared to just a single drive:
Redundancy
Redundancy is the key benefit of having two backup drives instead of one. If you only have a single backup and somehow that backup gets corrupted or the drive fails, then you’re left with no backup at all. Your data could be lost or severely at risk if your primary drive also fails.
Having a second backup drive gives you another copy of your data to fall back on if something happens to your first backup. This provides an important safety net against catastrophic data loss. If one backup fails, you can securely erase it and start over with a fresh backup copy on that drive.
Rotating Backups
Another major benefit of having two backup drives is that you can rotate making backups between them. For example, you could backup drive A on the 1st of the month, drive B on the 15th, then drive A again on the 1st of the next month, and so on.
This helps ensure that if either single backup fails, you still have a reasonably recent backup on the other drive. So you won’t necessarily have to go back a full month to the last backup if you were alternating drives.
Physical Separation
Keeping your two backup drives in separate physical locations reduces the chance of losing both backups to the same localized disaster.
For example, if you kept both backup drives at home and the house was destroyed by fire or burglary, you’d likely lose the backups as well. But keeping one offsite, say in a safe deposit box or at a trusted friend or family member’s house, ensures that even if you lose one backup the other should be safe.
Extra Capacity
There’s also the simple benefit that two drives doubles your total backup storage capacity compared to a single drive of the same size.
This provides room to grow – as the amount of data you have increases over time, you may need the extra space down the road if a single drive’s capacity becomes too small for holding full backups.
Potential Downsides
There are a few potential downsides to consider with using two backup drives instead of one:
Cost
The most obvious downside is cost. Buying two drives costs nearly twice as much as buying a single drive with the same specs. Granted, backup drives have become quite affordable and terabyte-sized drives can be purchased for under $50 in many cases. But it still is an added cost to factor in.
Effort
It also takes a little more effort on your part to alternate between two backup drives. You have to remember to swap drives and may need to adjust any automated backup scripts you’re using.
However, alternating backups manually or automatically is quite straightforward. And the minor extra effort is worth it for the added redundancy and data protection two drives provides.
Potential Confusion
One other consideration is that having two backup drives instead of one does introduce the (small) risk of confusion leading to mistakes. For example, you could accidentally restore older data from the wrong backup drive if you mix up archives.
Proper drive labeling is key to avoiding this issue. But it’s a rare downside to weigh when deciding between one or two backup drives.
Ideal Backup Drive Specs
If you do decide to use two backup drives, what specs should you look for when buying drives? Here are some key criteria:
Storage Capacity
Each backup drive should have sufficient capacity to hold at least a full backup of the data you want to protect. For most home users, 1-4 terabyte drives are likely sufficient. But consider future growth – you may want to size up if you anticipate large storage increases down the road.
Build Quality
Since reliability is crucial for backups, choose drives from reputable manufacturers like Western Digital, Seagate, Samsung, etc. Check reviews to confirm drives are built well and not prone to early failure.
Interface Type
Faster USB 3.0+ and Thunderbolt interfaces allow quicker backup writing and restoring. But if keeping costs down is the priority, USB 2.0 drives still work fine.
Warranty Length
Look for drives with at least 1-2 year warranties. This gives you a window to detect and replace any faulty drives.
Portability
If you want to store one of the drives offsite, portability is useful. Compact 2.5 inch drives and SSDs take up little space and can easily be kept in a safe, bank vault, etc.
Software Recommendations
Backup software, either standalone or built into your operating system, is required to automate the process of backing up to drives. Here are some top options to consider:
Time Machine (Mac)
Time Machine is built into macOS and provides automatic hourly backups to external drives. It’s easy to configure with multiple drives. Time Machine even keeps hourly backups for the past 24 hours so you can restore a file from earlier in a day.
Windows Backup and Restore
Microsoft’s own backup software is another built-in option, this time for Windows PCs. It lets you schedule full or incremental backups to external drives. Restore files easily from within the utility.
Veeam Agent (Windows, Mac, Linux)
Veeam Agent backs up not just files and folders but also system images for quick disaster recovery. Flexible scheduling and multi-drive support make it a good choice for redundant backups.
Duplicati (Windows, Mac, Linux)
Duplicati is a free and open source backup tool with a wide array of professional options like encryption, compression, scheduling, backups to cloud storage, and more. Worth checking out, especially for power users.
CrashPlan (Windows, Mac, Linux)
CrashPlan stands out for its forever-incremental backups to local drives and also remote backup option to their cloud service. Strong file versioning capabilities are included as well.
Alternative Backup Options
While redundant local backup drives substantially lower your risk of catastrophic data loss, for maximum protection consider adding offsite cloud backups as well:
Cloud Backup Services
Backing up copies of your backups online via cloud services covers you against a disaster destroying both local drives. Popular choices like Backblaze and IDrive have affordable ongoing plans.
Offline Media
For air gapped archival backups, external hard drives or flash drives kept in a secure remote location provide protection against malware or ransomware damaging online backups.
Physical Media
Finally, backing up your most essential data to physical media like high-quality Blu-ray discs or archival-grade CD/DVDs covers you if magnetic storage suffers corruption or failure.
Conclusion
To summarize the key points we’ve discussed:
- Two backup drives are better than one due to increased redundancy in case of failure.
- Alternating backups between drives provides more frequent updated archives.
- Physically separating drives reduces risk of losing both to a localized disaster.
- Added capacity from two drives allows room for future growth.
- Downsides are minor – mainly some extra cost and setup effort required.
- Ideal specs for backup drives focus on sufficient capacity, build quality, speed and warranties.
- Good backup software automates the process of dual drive redundancy.
- Consider additional cloud or physical media backups for maximum data protection.
Following the 3-2-1 backup strategy – with 3 copies of data, 2 being local but separate drives and 1 being offsite / cloud storage – provides excellent protection against data loss scenarios. Pairing local drive redundancy with additional backup layers is ideal.
In summary – yes, you should have two backup drives. The benefits of redundancy and expanded capacity outweigh the minor extra costs. Your data is precious, so give it the best protection you can by leveraging a pair of dedicated backup drives.
