I want to look at a raw block device (as in /dev/sda) and know how much space is being used on the drive.I don't know what type of file system is on the harddrive, nor do I have any way of figuring this out. A harddrive can obviously not be empty, but what I do know is empty space is represented as bunch of zeroes (as in, output from /dev/zero, not the ASCII character 0).How do I scan a block device, and then get an output telling me how many of the blocks are only filled with zero values?
How do I detect used harddrive space on a block device?
filesystems;block device