Tape Backup for Personal Use? The Hidden Costs and Modern Alternatives

As personal data collections expand into the tens of terabytes, many are exploring more robust backup solutions beyond simple external hard drives. One technology often mentioned is LTO tape, the long-standing choice for enterprise archiving. However, for personal use, the practicality, cost, and maintenance of a tape-based system present significant challenges.

The Economic Hurdle

The primary barrier to adopting tape for personal backup is the high upfront cost of the drive itself. While individual tapes may seem cheap per terabyte, the drive can cost thousands of dollars. The consensus suggests that tape only starts to become cost-effective when dealing with massive datasets, typically in the hundreds of terabytes to petabytes. For a 25 TB collection, purchasing a few large-capacity hard drives or SSDs is almost always a more economical choice.

Furthermore, it's important to note that the advertised capacity of tapes often assumes a 2:1 compression ratio. If your data consists of already-compressed files like videos or photos, you won't achieve this level of compression, making the cost-per-terabyte less favorable than it appears.

The Practicalities of Maintenance and Hardware

Beyond the initial cost, using tape at home comes with a steep maintenance curve. Key challenges include:

Hardware Compatibility: Most tape drives use SCSI or SAS interfaces, which are not standard on consumer motherboards, requiring an additional host bus adapter.
Drive and Tape Wear: Tapes shed a small amount of their magnetic oxide coating with each pass. This residue builds up on the drive's heads and guides, requiring frequent cleaning to prevent read/write errors and ensure backups are valid. Failure to do so can render your backups useless.
Long-Term Reliability: Tape drives are complex mechanical devices. Over a decade of storage, you might find that the drive's belts have perished or other components have failed, preventing you from restoring data even if the tape itself is fine.

A Modern Alternative: The Multi-SSD Rotation

One contributor outlined a compelling alternative to tape that prioritizes both reliability and convenience. The strategy involves:

Diverse Hardware: Using a combination of SSDs and NVMe drives purchased quarterly to diversify the hardware and avoid potential failures from a single manufacturing batch.
Robust Software: The drives are encrypted using dm-crypt. The initial backup is a full copy (cp -aR), while subsequent updates use rsync -aqhH for efficiency. A full --checksum is performed periodically to verify data integrity.
Physical Off-Site Backup: Each full backup is treated as a point-in-time snapshot. These sets of drives are stored in separate, secure metal boxes, with one set always kept off-site (e.g., in a vehicle) for disaster recovery.

This method avoids the high entry cost and maintenance of tape while offering faster, random access to files, which is a significant advantage over the sequential nature of tape when you need to restore a single file.