Backup file size discrepancy


I saw a couple of strange things with our backups and would love a little bit of clarification on why stuff was happening.

First of all, running ls -l --block-size=GB on the /backups/default/ directory shows that each one is 7 GB.
The website displays them to be 5.8 GB large.

When I scp’d one of those to another test server and uploaded it the file size displayed was 2.1 GB for maybe 20 minutes and then later changed to display as 5.8GB.

I’m guessing it just took a while to figure out the proper size but it’s still off by a lot?? What’s going on here?

Also the GUI buttons to download backups are not working at all for us and I need to just grab the files off our server. I saw other’s suggest to just do what I did in that situation but does anyone know why that would happen?