The rule professionals use
3 copies of your data On 2 different storage media With 1 copy offsite
This is the 3-2-1 rule. It's been the gold standard for 40 years and it still is, because the failure modes haven't changed: drives die, fires happen, ransomware encrypts your working files and your backup drive if both are plugged into the same machine.
Why each part matters
3 copies: one is your working copy, two are backups. If both your working drive and one backup fail simultaneously (more common than you'd think — a power surge can take out everything plugged into the same strip), you still have one.
2 different media: if everything is on spinning hard drives from the same manufacturer bought on the same day, they'll fail together. Mix SSD + HDD, or local + cloud, or external disk + tape. A malware that hits Windows file systems likely won't hit your cloud-snapshot backup.
1 offsite: fire, flood, theft. If your house burns down, your carefully-kept external drive on top of your PC burns with it. Offsite can be a relative's house across town, a bank locker, or cloud storage.
A realistic setup for a home user
- Copy 1: the files on your laptop you work with daily
- Copy 2: a ₹4000 external 2TB hard drive you plug in once a week and run a backup to. Keep it unplugged otherwise so ransomware can't reach it
- Copy 3: cloud backup (Backblaze at $9/month, OneDrive 1TB, iCloud 200GB, or Google One) set to run automatically in the background
Three copies. Two different media (local disk + cloud). One offsite (the cloud is by definition elsewhere).
For Windows users — software recommendations
- Macrium Reflect Free — full system image backups. If Windows dies, restore the whole machine in 20 minutes.
- FreeFileSync (free, open source) — folder-to-folder sync with versioning. Dead simple.
- Backblaze — $9/month, unlimited cloud backup, truly set-and-forget.
- Veeam Agent Free — proper enterprise-grade backup for personal use.
Avoid: "PC Cleaner" apps, any backup tool you've never heard of, anything that requires a subscription but doesn't show you actual restore test results.
Test your restore
A backup you've never restored is not a backup. Every six months, pick a random file from your backup and actually restore it to a different location. If that fails, you'd be in serious trouble during a real disaster. The day you need a backup is the day you find out your backup was broken three years ago.
Ransomware specifically
Ransomware encrypts everything it can reach, including attached backup drives. To survive ransomware, at least one of your backup copies must be offline or immutable. Cloud services with versioning (Backblaze, Google Drive) keep older versions for 30 days by default — that's your ransomware insurance.
Takeaway
Most people have zero backups and don't realise it until the drive fails. One external HDD + one cloud subscription gets you to the 3-2-1 standard. ₹400/month for peace of mind is nothing compared to losing 10 years of photos.