Storage and Backup: Keeping Your Files When a Drive Fails

Every drive fails eventually. The only question is whether it fails before or after you have a copy of what is on it. Most people find out which in the worst way.

Storage is not backup

A second copy on the same machine is not a backup. Nor is a folder that syncs — sync services propagate deletions and corruption to every copy, which means a mistake or ransomware reaches your "backup" within seconds.

A backup is a separate copy, on separate hardware, that is not continuously connected.

The rule worth following

The widely used guideline is three copies, on two different types of media, with one kept off-site.

In practice for a household: the working copy on your computer, an external drive kept at home, and a cloud backup. That covers drive failure, accidental deletion, and losing the house to fire or theft.

Automate it. A backup that depends on remembering is a backup that stops after three weeks.

Choosing a drive

• SSD or hard drive. SSDs are faster, silent, and survive being knocked about — better for anything portable. Mechanical hard drives cost far less per terabyte — better for bulk storage that stays on a desk.
• Interface and cable. Check what connection the drive needs and whether your machine has it. A fast drive on a slow port is a slow drive.
• Whether it needs mains power. Larger desktop drives usually do. Portable ones usually do not.
• Warranty length, which is a reasonable proxy for expected life, though it never covers the data.
• Encryption, if the drive leaves the house. Built-in encryption or software encryption both work; unencrypted is a problem if it is lost.

Be wary of very cheap high-capacity drives from unknown sellers — a known failure mode is firmware reporting a capacity the hardware does not have.

Cloud backup

Different from cloud sync, though the same companies sell both. Points to compare:

• Whether it keeps version history, and for how long. This is what saves you from ransomware and from overwriting a file.
• How long deleted files are retained.
• Total cost per year, including whether it is per device or per account.
• Restore process and speed. Backing up is easy; restoring is the part you should test.
• Where the data is stored, if that matters for your work.

Test the restore

An untested backup is a hypothesis. Once a year, restore a handful of files and confirm they open. This takes ten minutes and is the only way to know the system works.

What to back up first

Irreplaceable things: photographs, documents, records, anything you created. Software and films can be downloaded again; your own files cannot. If storage is limited, prioritise on that basis rather than backing up everything equally.

Before you order

Check the interface matches your machine's ports. Check whether the drive needs mains power if it needs to be portable. For cloud plans, check version history length and the total annual cost rather than the monthly headline. And whatever you choose, set it to run automatically before you file it away as done.