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Comment by programmer_dude | Hacker News Reader

What is a drive image? Is it a standard like ISO?

It's the result of 'cat /dev/sda >drive.img', basically. It's not that different from an "ISO image", which is the same except for the CD-ROM drive (I forgot which device name that is). An ISO image is just a "drive image" with the ISO9660 filesystem.

(Live images like this typically do have different bootloaders than your regular/dev/sda).

That's generally called a "disk image", not a "drive image", which is a term I had never heard before in my over 30 years of using computers and seems to almost exclusively be used with relation to some proprietary software program that happens to have that name.

I would say 'cat /dev/sda >disk.img' is a "disk" image since it bitwise includes all sectors with partitions in order and everything on the source HDD.

You would restore a disk image to an entire HDD of at least the same size as the original, with compatible geometry when applicable.

OTOH 'cat /dev/sda1 >drive1.img' would be an image of only the first partition, making it a "drive" image of that one volume alone.

You could restore such a "drive" image to any partition of the same or larger size. Bootability would still be dependent on considerations outside that one volume.

(Sibling comment already explained the concept of an image.) Yes, the boot process from this kind of image is just as standardized as an ISO.

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