I'm trying to back up some PC game discs and I'm confused about the difference between using the dd command and simply dragging the files to another location. dd seems to fail fairly often, while copying the files feels much more reliable. If I copy everything from a game disc, can I use those files to install or run the game, or do I need to create a complete disc image with dd?
3 Answers
The dd command doesn’t understand filesystems—it just reads from one device or file and writes the bytes somewhere else. That makes it useful for exact images, but a wrong input or output device can cause failures or overwrite data. Dragging files is safer and is fine when you only need the install files and the game doesn’t require a complete disc image.
If you mean an optical game disc, you probably want to create an ISO or another disc-image format rather than use plain file copying. An image preserves the disc structure and can be mounted or written to a replacement disc. Whether it works for a particular game also depends on copy protection, since some older discs used data that ordinary copying won’t reproduce.
Drag-and-drop copies the visible files and folders, so it’s a file-level backup. The dd command copies raw bytes sector by sector, including the filesystem, partition or disc layout, unused areas, and other metadata. They’re meant for different jobs rather than being interchangeable.
So copying the contents might be enough for installing the game, but it wouldn’t necessarily preserve the entire disc exactly?