I am new to Duplicacy and I am trying to backup up my Windows 10 PC, specifically the C drive, to Backblaze B2.
When I try to run the backup I get loads of " Failed to read the symlink" errors in the log.
What am I doing wrong? Can I even backup a “live” drive with Duplicacy?
There’s nothing you are doing wrong.
If you want to be sure all data is there, you can just perform a restore to a new folder, and see what files and folders 
included and excluded. This will also help you decide what you don’t need to backup (there are a lot of folders in /AppData/Microsoft/* which 
aren’t needed).
There are some folders (symlinks) which windows provides “for itself” but no other application has access to them (and windows is too lazy to hide those folders), so it’s normal to see those messages, especially if they are in \AppData\.
There also are some files which just can’t back up, for example when chrome is running, or from “modern” Windows apps because they use some special kind of lock files.
You may want to try and backup a live drive with the option -vss, like: duplicacy.exe backup -vss -other -options (ref: Backup command details) which is a windows feature that creates a “read-only snapshot” of the filesystem. Unfortunately, outlook for example doesn’t work with that feature (because, you know, microsoft doesn’t make both windows and outlook so it totally can’t fix their shit). To use this option you need to run the backups as an administrator.
What you could also do is try to use the Filters/Include exclude patterns to remove some useless folders from the backup. I have already created a default file that (imo) almost everyone can use: my filters file.
Thanks for reply.
How do I specify --vss from the GUI?
(I think I will do a restore to a spare drive just to check, is a restore faster than a backup? async broadband and all that?
Since you’re on broadband i recommend you do this: initialise a new repository just like the previous one, but in this case use the external hdd as the storage (just for testing purposes). In this way you won’t have to wait until everything goes through the internet, but run at USB speeds!
By doing this you will be able to test backup, restore, second backup, filters, etc. much more easily.
I have to ask though: what kind of gui do you use? web-ui, or the native gui?
Unfortunately idk how to do that, as i only use the command line version. Does this help you: Windows GUI- question on VSS ?
Native GUI at the moment