When selecting data partition on my phone (HTC One M8), TWRP says it's going to back up 5448 Mb. But 'df' command says there are 8319 Mb used from 10934 total. And ES Explorer displays the size of /data directory as 11.32 Gb. How are these figures related? I'm at a loss trying to explain that.
Here is the screenshot of DiskInfo:
Here is the screenshot of Diskusage: