how to find the no of data block in a partition?

Question

A disk.img of 100mb using dd been created,then i've made three partions using fdisk 1.boot(vfat)40mb, 2.root(squashfs)40mb, 3.dummypartition(20mb). now i have to calculate the number of data blocks in the squashfs ie: root partition, for setting up the dm-verity. so how to calculate it.

Answer 1

Use the "debugfs" tool to view file info on the command line terminal

# debugfs /dev/<partition>
# stat /path/to/file

Or

# debugfs -R "stat /path/to/file" /dev/<partition>

For example:

  # debugfs -R "stat /etc/group"  /dev/sda3