May 17, 2023, 11:26am
The documentation on [how to backup, restore and migrate](
How to back up, restore, and migrate | Qubes OS) says,
"When backing up dom0 using the Qubes backup tool (explained below), only the home directory is backed up. Therefore, if there are files outside of the home directory you wish to save, you should copy them into the home directory prior to creating a backup."
However, when I use the Qubes backup tool it shows the size of the dom0 backup is going to be 7.1 GB, but other than about 20 MB of screenshots in `/home/Pictures/` I don't have anything in `/home/`.
Why then does the Qubes backup tool report the dom0 backup is going to be 7.1 GB. What is it then backing up?
However, when I use the Qubes backup tool it shows the size of the dom0
backup is going to be 7.1 GB, but other than about 20 MB of screenshots in
`/home/Pictures/` I don't have anything in `/home/`.
It's a bug in the GUI backup tool's size calculation for dom0:
04:58AM - 29 Feb 20 UTC
**Qubes OS version**
Qubes release 4.0 (R4.0)
**Affected component(s) or fun
"Backup Qubes" wizard
On the page where you select which qubes to include in the backup the size of each qube is overestimated.
1. Start the "Backup Qubes" wizard
2. On the initial page note the total backup size
3. Clink next 2 times
4. Compare total size to the one reported on the summary page
A reasonably accurate estimate of the contribution of each qube to the backup size and the total backup size should be displayed.
The size appears to be severely overestimated. In particular:
1. dom0 is reported to be tens of GiB in size
2. Any qube that is running at the time is reported to have a much bigger size than it actually has
In case it matters: my primary pool is a btrfs-backed file-reflink. I understand that it is impossible to predict the effectiveness of backup compression. This issue in not about compression, but specifically about two wizard pages disagreeing on the backup size.
**Relevant [documentation](https://www.qubes-os.org/doc/) you've consulted**
**Related, [non-duplicate](https://www.qubes-os.org/doc/reporting-bugs/#new-issues-should-not-be-duplicates-of-existing-issues) issues**