(Software Update Required) X450G2-48t-10G4.16 # upload configuration X.X.X.X primary.cfg vr "VR-Default"
Uploading primary.cfg to 10.218.50.20 ... failed!
Error: (1) File not found
(Software Update Required) X450G2-48t-10G4.17 # ls
-rw-r--r-- 1 root root 297552 Apr 12 17:03 primary.cfg
The "upload config" command by default uploads your current running configuration to a .xsf (or text file) on the tftp server that you define. In the command the name you supply should be something like "primary" without an extension, it will copy and save it on the tftp as "primary.xsf" - If you want to copy the raw file you can use "tftp put" command. Let me know if you have any other problems or questions!
This obscure mechanism is still implemented in many TFTP servers on Linux systems, but not widely known any more.
The error message "Error: (1) File not found" is typical for this kind of problem.