That time my 100GB of files turned out to be 2GB 💾 - u/LetIt

New Name · 2026-06-14T12:03:05.134Z

Quick story that might save you some confusion for USB HD. My Mac nagged me about low storage, so I moved a folder of old project files onto a 1TB USB drive. Simple cleanup, right? Except the USB said the folder using 100GB . I started side-eyeing my SSD like it had scammed me. Turns out: it didn't. And neither did the Mac. Here's what was actually going on. That folder was full of programming files. Think tens of thousands of tiny files, the kind that pile up in things like node_modules . USB drives are usually formatted as exFAT, and exFAT stores files in big fixed-size "slots." So every tiny 1KB file grabs a whole slot and wastes the rest. Multiply that by thousands of files and 2.5GB of real data looks like 100GB on the drive. The fix was almost funny. I just zipped the folder , and it collapsed down to 2.5GB . Same files, no wasted slots. Two things I'll remember for next time: Lots of small files such as code, projects? Zip them before putting them on a USB. Huge space savings. Videos, photos? Don't bother. They already pack tight, just drop them in as-is. One bonus gotcha: if you ever need those files again, don't unzip them on the USB. It will balloon back to 100GB. Pull the zip onto your computer first, then unzip. Your Mac's drive doesn't waste space the way exFAT does. Anyway, not a defective drive, just a sneaky formatting quirk. Hope this saves someone.

That time my 100GB of files turned out to be 2GB 💾 - u/LetIt | LetIt