Windows: external hard disk recognize (usb variable drive letter)

Hallo,
I use duplicati for a local backup on a usb disk.
The problem is that disk changes the letter each time it’s mounted, so I have to edit duplicati’s task. I wish I can tell Duplicati wich disk to use without the need of the disk letter.
Freefilesync can do that, so I guess it’s possible (here’s the man page: https://freefilesync.org/manual.php?topic=variable-drive-letters).
Thank you

Hello @andrearicci, welcome to the forum!

There are a few ways to handle drive letter issues in Windows, but for me the easiest way is to use the --alternate-destination-marker and --alternate-target-paths parameters.

Essentially you can put a “magic file” in your backup drive folder and add something like --alternate-destination-marker=[magic file name] to your backup. This will tell Duplicati to only back up to your drive if it finds the magic file.

By using that with something like --alternate-target-paths=*:\backups your tell Duplicati to use the \backups folder on ANY drive as long as it contains the “magic file”.

By doing this you can even have different backups going to different drives even if they get the same drive letter when attached - as long as you use either a different path and/or a different “magic file”.


See this page for more info about this annoyance:

thank you,
I’ll study.

sorry to be so late, thank you, that solved my problem.
Just a note for other users: the magic file has to be inside the backup folder, not just the drive.

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Thanks for the followup and the tip! I’ve updated my post to reflect it. :+1: