Make Linux ext2 file system disk image

Question

How do you construct a file system disk image and then look at its disk layout in bitmap files? How do you add directories to it?

I've used mkfs.ext2 on a file that I made using dd, but I'm not sure if it’s done correctly.

I need to be able to see the inodes and inode table and see how they relate to the blocks.

Answer 1

Use dd, mkfs.ext{2,3,4}, and losetup to create a disk image, a file system and mount the device.

Next, you may want to explore and learn using debugfs - ext2/ext3/ext4 file system debugger. This has a lot of commands, bmap, dump, dump_extents and many more.

Additionally, if you want to read the file system meta data and debug, it would be good idea to explore the tune2fs, and e2image commands which would require a good understanding of file system internals.