Can I leave my external hard drive plugged in continuously, even when the computer is turned off? Will keeping it connected reduce the drive's lifespan, and does it only wear out while files are being read or written? Also, is it safe to disconnect a spinning external HDD without ejecting it first?
3 Answers
Leaving it connected usually isn’t a problem. When the computer is off, the drive generally isn’t spinning or doing anything, although some USB ports can still provide power. The bigger risk is moving, bumping, or dropping the drive while it’s spinning. If the data matters, keep another backup instead of relying on this drive as the only copy.
It can spin during reads, writes, indexing, or background maintenance—not just during obvious file transfers. Many drives also stop spinning after sitting idle.
An external hard drive works much like an internal mechanical drive. It’s fine to keep it connected, but avoid physically moving it while the platters are spinning. If you don’t need it constantly, safely ejecting it and switching it off when finished can reduce unnecessary operating time, though normal use shouldn’t dramatically shorten its life.
You can generally connect an external drive while the computer is running, but safely eject it before unplugging it. This applies to mechanical drives regardless of whether they use FAT32, exFAT, or NTFS. The file system can affect how damage appears after an unsafe removal, but it doesn’t make unplugging a spinning drive risk-free.
I think the drive is formatted as FAT32. I’ll still eject it before unplugging so I don’t risk corrupting the files.

Does the drive only move when files are being copied, or can it spin at other times too?