Guide

Rotating backup drives: a simple routine for a small office

A backup drive that never leaves the desk shares every risk the PC has. Two drives, swapped once a week, fix that for the price of a second drive.

Updated October 2026

Why one drive isn't enough

• Fire, flood, and theft take the PC and the drive next to it together.
• Ransomware scrambles every drive it can reach – including a backup drive that's plugged in.
• Drives fail. A backup drive is a hard drive too, and can fail on the day you need it.

The usual rule of thumb is three copies of anything important, on two different kinds of storage, with one away from the office. Two rotating drives plus the PC itself gets you there.

The routine

1. Buy two drives, each comfortably bigger than what you back up, and label them – "Drive A" and "Drive B", or "Week 1" and "Week 2".
2. Back up to Drive A all week.
3. On Friday, swap: take Drive A home (or to another office, or a safe), and plug in Drive B.
4. Next Friday, swap back. The drive at home is never more than a week old.

A week is a good balance for most offices. If losing a week's work would be serious, swap more often – or add a daily backup to a NAS as well, and keep the rotating drives for the copy that's away.

Make it hard to forget

Rotation only works if the swap happens. Put it in the calendar for the same day each week, and make it one person's job. Check now and then that the drive coming back into the office actually has a recent backup on it.

Protect the drives that travel

A drive in a bag can be lost. On Windows 11 Pro, BitLocker locks a drive with a password, so whoever finds it can't open your files. Keep the recovery key Windows gives you somewhere other than the PC.