I just backed up the contents of my home partition onto my external hard drive using Back In Time. I browsed to the backed up contents in the external drive and under properties it showed me the size as 9.6 GB.
As I read that in next snapshots I create, Back In Time does not backup everything but creates hard links for older contents and saves newer contents, I wanted to test it. So I copied two small files into my home partition and ran 'Take Snapshot' again.
The operation completed within a minute - first it checked previous snapshot, assessed the changes, detected two new files and synced them. After this when I browsed to the backed up contents, I was surprised to see the newer and older backup taking up 9.6 GB each.
Isn't this a waste of hard drive space? Or did I interpret something wrongly?
It seems that checking properties under context menu is not reliable in such cases. When I used
ducommand it showed right usage. I could get this suggestion from Launchpad's 'Back in Time's' Mr. Dan.This is because backintime uses hard links, where each file is stored once, but makes it look like each copy takes up additional room. For more details please refer to https://answers.launchpad.net/backintime/+question/146072.
My guess is that your external hard drive is formatted FAT32 or some other file system that does not support hard links. It also appears that if the partition type containing the file system is not a Linux (0x83) partition, the file system will not properly record the disk consumption of the hard links. If you create a Linux native partition on your external hard disk and format it with a native Linux file system such as ext4 it should work properly.