Error in /var. , no space, I think

i’ve this errore “Disk full. Path /var/folders/3f/5n8r4871369bznrq_58n27pw0000gn/T/dup-351c8e2e-f8e9-4ce9-858b-53a20abdc16f”.

I think, that there is not enough space on the drive where the /var folder and the rest of the program resides, which is the main drive where the operating system and all the other programs reside, at the moment I have 200 GB free, but the data to be backed up is over 1 TB with encryption. It is possible to move the /var folder to another drive, I have a partition with 4 TB free… (the one that should host the backup).
I have OSX, latest version under MacMini M1.
Thank you

Welcome to the forum @Davide_Facciabene

Is this perhaps the temporary folder seen in command line by echo $TMPDIR?

This name looks like a Duplicati temporary file name, and would fit that theory.

Does that file still exist? What size? What do you read for free space in folder?
Asking about folder specifically since I don’t know how your space got divided.

Shouldn’t fill up unless you made huge Remote volume size on Options screen.
Its default is 50 MB (and read description). What do you have that value set to?