If your external drive is always plugged in, it isn't a backup

Credit: Patrick Campanale / How-To Geek Published Aug 7, 2026, 1:20 PM EDT Monica J. White is a journalist with over a decade of experience in covering technology. She built her first PC nearly 20 years ago, and she has since built and tested dozens of PCs. PC hardware is her main beat, and graphics cards and the GPU market at large are her main area of interest, but she has written thousands of articles covering everything related to PCs, laptops, handhelds, and peripherals. From GPUs and CPUs to headsets and software, Monica's always willing to geek out over all things related to computing. Outside of her work with How-To Geek, Monica contributes to TechRadar, PC Gamer, Tom's Guide, Laptop Mag, SlashGear, Whop, and Digital Trends, among others. Her ultimate goal is to make PC gaming and computing approachable and fun to any audience. Monica spends a lot of time elbow-deep in her PC case, as she's always making upgrades, testing something, or plotting out her next build. She's the go-to tech support person in her immediate circle, so she's never out of things to do. Whenever she has spare time, you'll find her gaming until the early hours and hanging out with her dog. Sign in to your How-To Geek account If you've ever put too much faith in a storage device, you're not alone. We've all been there. It doesn't matter if you're buying a portable SSD, an NVMe drive that goes inside your PC, or even a good old HDD—the risk of data loss is always real, and always mildly scary. The problem is that many people are still doing backups the wrong way, or are unaware of the various points of failure along the chain of data. These are the major issues with many backups, and how to fix them. A single drive is never a backup It's better than nothing, and that's about it. Credit: Tim Rattray/How-To Geek It's easy to feel like your files and photos are safe as long as you have a single portable drive to store them on, but this couldn't be further from the truth. In fact, this goes against the (perhaps outdated) 3-2-1 backup rule, and it's never enough. The sad truth is that if your files or photos only exist in one place, you don't have a backup; you just have a storage device that can fail at any given time. With photos, most of us also back them up to the cloud, often without meaning to, but files? It's the wild, wild west out there, and I know many people who have a 10-year-old HDD as the only thing that stands between them and data loss disaster. Beyond just placing too much trust in one device, these "one drive" backup setups fail for reasons that often have nothing to do with the drive itself. One unfortunate disconnect during file transfers can lead to data corruption, especially on older devices. The next problem is exposure. If your backup drive is always plugged in, it's essentially vulnerable to all the same stuff as your PC, from ransomware to power loss. If it's not, it might die from being idle, and you won't even know until it's too late. Then, there's the file system. Unplugging your drive during transfers is one thing, but unplugging it during background writes is just as common, and you might not even see that the OS is doing some indexing work behind the scenes. If you're using exFAT for compatibility, you'll find that it's less forgiving if the drive gets yanked or randomly disconnects mid-write. This can mess up the entire file system, even if your files were intact just a moment ago. External drives can fail in more ways than you think And each option leads to disaster. Credit: Patrick Campanale / How-To Geek Monitoring your SSD health can help prevent disaster, but depending on the type of backup device you use, you might have quite a task ahead of you. SSDs can fail even at 100% health, and the same can be said of other types of media, from HDDs to USB drives. Outside of regular drive failure (which is likelier to happen if your drive's been in use for years, or, conversely, laid forgotten in a drawer somewhere), there are other risks to consider. Physical damage is a big one here, and it ties into why it's not a good idea to keep all of your backups in one location. If you drop the drive, there's a power surge, or your drive gets taken for a bumpy ride inside your backpack, it might not make it out alive. Random disconnects may still cost you data even if the drive makes it out unscathed, so while not a failure per se, they're still dangerous. Portable HDDs can develop bad sectors, as can SSDs. Some of these issues may not kill the drive, but can still damage your backups. Quiz8 Questions · Test Your KnowledgeData backups and the 3-2-1 ruleTrivia challengeThink you know how to keep your data safe? Test your knowledge of backup strategies, rules, and best practices.Backup RulesStorageStrategyRecoverySecurityBeginWhat does the '3' in the 3-2-1 backup rule refer to?A3 different cloud storage providersB3 total copies of your dataC3 separate backup schedulesD3 different file formats for each backupThat's right! The '3' means you should maintain 3 total copies of your data — the original plus two backups. Having multiple copies dramatically reduces the risk of total data loss from any single failure.Not quite. The '3' refers to keeping 3 total copies of your data, including the original. This redundancy ensures that even if one or two copies are lost or corrupted, you still have a surviving copy to restore from.ContinueIn the 3-2-1 backup rule, what does the '2' stand for?A2 full backups and 1 incremental backupBBacking up data at least twice per weekCStoring copies on 2 different types of storage mediaDKeeping 2 offsite copies at all timesExactly! The '2' means your copies should be stored on at least 2 different types of media — for example, an external hard drive and a cloud service. This protects you from media-specific failures like a hard drive manufacturer defect.Not quite. The '2' in the 3-2-1 rule refers to using 2 different types of storage media, such as a local NAS drive and a cloud service. Diversifying your media types guards against failure modes that might affect one type but not another.ContinueWhat does the '1' in the 3-2-1 backup rule specify?AAt least 1 backup should be encryptedBAt least 1 copy should be stored offsiteCAt least 1 backup should be tested monthlyDAt least 1 copy should be kept on physical mediaCorrect! The '1' means at least one copy must be stored offsite — away from your primary location. This protects your data from local disasters like fires, floods, or theft that could destroy everything stored in one place.Not quite. The '1' requires that at least one copy be stored offsite, such as in a cloud service or at a separate physical location. Local disasters like fires or floods can wipe out everything in a single building, so offsite storage is a critical safeguard.ContinueThe 3-2-1-1-0 backup strategy adds two extra elements to the original 3-2-1 rule. What does the second '1' represent?A1 backup stored in a write-once, read-many (WORM) or air-gapped formatB1 backup verified by a third-party serviceC1 backup stored exclusively on tape mediaD1 dedicated backup administrator responsible for the processSpot on! The second '1' means one copy should be offline, air-gapped, or immutable — such as a WORM drive or tape that ransomware cannot reach and overwrite. This is a critical defense against modern ransomware attacks that specifically target connected backups.Not quite. The extra '1' in 3-2-1-1-0 stands for one copy that is offline, air-gapped, or stored in an immutable format like WORM media. This prevents ransomware or malicious actors from encrypting or deleting all your backup copies simultaneously.ContinueIn the 3-2-1-1-0 rule, what does the '0' at the end signify?AZero backups should be stored in a public cloudBZero unverified backups — all backups should be tested for errorsCZero days between each backup sessionDZero physical media copies allowed in the strategyExactly right! The '0' means zero backup errors — all backups should be verified and tested to ensure they can actually be restored. A backup you've never tested is not a reliable backup, as corrupt or incomplete backups offer false security.Not quite. The '0' stands for zero errors, meaning every backup should be verified and confirmed restorable. It's a common but dangerous mistake to assume backups work without testing them — many organizations have discovered corrupted backups only when they desperately needed them.ContinueWhich of the following backup types only saves data that has changed since the last FULL backup, regardless of any incremental backups in between?AIncremental backupBDifferential backupCMirror backupDSnapshot backupWell done! A differential backup saves all changes made since the last full backup, growing larger over time until the next full backup is performed. Compared to incremental backups, restoring from a differential backup is faster because you only need two sets: the last full backup and the latest differential.Not quite. That's a differential backup. Unlike incremental backups (which only save changes since the last backup of any type), differential backups capture everything changed since the last full backup. This makes them faster to restore but they consume more storage space over time.ContinueWhat is the term for the maximum amount of data loss a business or individual is willing to accept, measured in time, when a data loss event occurs?ARecovery Time Objective (RTO)BMean Time Between Failures (MTBF)CRecovery Point Objective (RPO)DData Loss Threshold (DLT)Correct! Recovery Point Objective (RPO) defines how much data you can afford to lose, measured in time — for example, an RPO of 4 hours means you back up every 4 hours and can tolerate losing up to that much work. It directly determines how frequently you need to perform backups.Not quite. The correct term is Recovery Point Objective (RPO), which defines the maximum acceptable age of the files you need to recover after a failure. RPO is different from RTO (Recovery Time Objective), which measures how quickly you need to be back up and running after an incident.ContinueWhy is it generally recommended that at least one backup copy be kept 'air-gapped' in a modern backup strategy?AAir-gapped backups compress data more efficiently than connected storageBRegulatory compliance in most countries legally requires an air-gapped copyCAir-gapped backups are immune to ransomware and remote attacks since they have no network connectionDAir-gapped storage reads and writes data faster than cloud alternativesExactly! An air-gapped backup is physically isolated from any network, meaning ransomware and remote attackers cannot reach it to encrypt or delete it. As ransomware increasingly targets connected backup systems, an air-gapped copy serves as the last line of defense for guaranteed recovery.Not quite. The key benefit of an air-gapped backup is that it has no network connection, making it completely unreachable by ransomware, hackers, or remote attacks. Modern ransomware strains are specifically designed to find and encrypt connected backup drives, so an offline copy is your most reliable safety net.See My ScoreChallenge CompleteYour Score/ 8Thanks for playing!Try Again The drive isn't the only thing that can fail It's far from the only link in that chain. The drive itself is just one part in a long list of tech that all adds up to a backup solution. The full chain is your USB port, the cable, any hub or dock, the enclosure's USB bridge controller, and the file system. A failure anywhere along that line still means your files could be in danger. Cables are the easiest thing to overlook. A slightly loose plug or a cable rated below spec or only for charging can cause micro-disconnects during file transfers, damaging data integrity. Ports and hubs are notorious here, too. Not only do they kill your transfer speeds, but they can also drop data transfers, especially if you're connecting via a hub instead of directly. Enclosures can add a layer of risk, too. Putting your SSD in an enclosure is a good solution if you have an older drive lying around, but cheap SATA to USB or NVMe to USB bridge chips can overheat or crash. And even if everything else is perfect, one bad disconnect or power surge can corrupt the directory structure. Just one glitch is all it takes to lose all your files if all you have is a single backup. The habits that kill your backups And how to do better. Credit: Patrick Campanale / How-To Geek There's nothing wrong with backing up your photos or files on an external drive, but you should always treat it as the risk that it truly can be. It's convenient to have a portable SSD always plugged into your PC, but it's just an extension of your existing storage instead of a proper backup. That's the biggest habit that can backfire: treating your backup drive like a second internal drive. If it's always connected, always writable, and you always move and edit files directly on it, you're making it part of the same failure event as your computer ... which means it can't be a proper backup. Many of us also tend to lean on cloud storage, expecting it to be good enough. I'm definitely guilty of letting my photos back up to a Google Drive and forgetting about it. But trusting a third-party service means that you're not in full control of what happens to your files, and without being alarmist, it's always better to know you have something else to fall back on. So, how do you fix this? Treat your precious data the right way You can't fully prevent drive failure, so instead, treat every backup as the fallible device that it truly is. Never assume it'll be fine, as it might crash at any given moment. (It probably won't, but this is where you decide what's more important: convenience or your files.) Keep one backup drive offline by default. Don't plug it in unless you have to, but do check on it once every few months to monitor its health. Keep a second backup, ideally in a different physical location. If you have an always-connected drive, don't rely on it to keep your files safe. Also, adopt a quick routine that catches problems early. Once a month, pick one random folder, copy it to a different location, and check that all the files are opening and playing correctly. Sometimes SSD health programs will tell you that the drive is fine, but copy errors happen during transfers and won't be spotted by software.