Re: [Libguestfs] Read MBR and store in a file?

On Fri, Nov 22, 2013 at 01:58:24PM +0000, adrelanos wrote: > Hi! > > Is it possible to read the MBR of an image and to store it inside a file? Yes, easily :-) guestfish --ro -a disk.img run : pread-device /dev/sda 512 0 > mbr This will work for any format of disk. Of course for a raw format disk this is just a slower way of reading the first 512 bytes from the raw file. Since what you want are simply virtual sectors from a disk image, it could be quicker to use qemu-io. Something like this: qemu-io -c 'read -v 0 512' disk.img (Unfortunately the format returned by qemu-io is a hexdump which is not exactly useful ... I can't work out how to get it to dump the raw bytes but there may be a way.) > (If you want to know what I really want to do: > Creating a report on all contents of an vm image. [1] [2] Create the > image on two different machines, compare them and see, that there are > no important differences besides temporary files.) > > Cheers, > adrelanos > > [1] https://github.com/Whonix/Whonix/issues/113 > [2] https://github.com/Whonix/Whonix/blob/master/release/analyze_image You might also want to take a look at virt-ls (although that *only* compares files, not the other data outside the filesystem): http://libguestfs.org/virt-ls.1.html#differences-in-snapshots-and-backing... I keep meaning to write a comprehensive "virt-diff" tool. I needed it myself just yesterday. Rich.