(size) to go larger than source size

Running an initial backup of my system I see that the size displayed in the “to go” section of the GUI is much larger than the actual size of the source. The progress shows a little over 400GB to go, but the source is only about 260GB.

Just want to be sure this is just some inconsistency in reporting and that the compressed cloud backup won’t really be larger than the source?

Thanks for using Duplicati and posing this question, wgstarks!

Is it possible Duplicati is following symbolic links in a way that whatever tool you’re using to check source size doesn’t follow?


For an initial backup (so no version history yet) the only way for the destination to be larger than the source is there’s no compression and no deduplication (either due to file types or parameter settings).

If those two things happen then the natural overhead associated with archive files (even with zero compression) and Duplicati’s related index files would make the destination SLIGHTLY larger than the source - but this is likely a few megabytes here, not the gigabytes you’re seeing.


There have also been a few scenarios identified where the source sizes in the progress bar appear to be “off” - do either of these topics match up with your experience?

(I know this second one isn’t specifically about the progress bar, but I thought I’d include it just in case.)

I’m basically backing up my startup volume (excluding system files) and my iTunes library which is on a seperate volume. Used “Get Info” to check the sizes of the two locations and added them together to get the size of the source.

I’m not sure that either of the posts you linked really matches this scenario. I just don’t know enough about Duplicati to say for sure. I’ll let the initial backup continue and see what the end result is.

Heh - and I don’t know enough about Macs to know if Get Info automatically follows or hides anything. :slight_smile:

As far as Duplicati is concerned it works at the file (not disk) level so it only backs up files it can see. So (for example) if you have a file system that stores older versions of files in some way, Duplicati won’t back up the older versions - only the version that is normally shown in your Finder or file browser.

Since this is a Mac, my GUESS is that there’s some cross linking going on between folders so Duplicati is counting certain files twice in it’s size calculations. But during the actual backups it will see that they are the same files and only back them up once.

Wonderful plan! Let’s let empirical evidence help us figure out what’s really happening. :slight_smile:

Note that /Volumes/Macintosh\ HD/ is a symlink back to / causing a circular reference.

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