Hello Hannes De Bondt, What you can do is that if you have the web utility configured on the TL4000 you can upgrade the firmware that way.  Once you have logged into the web utility you are going to need to go to Service Library Menu upgrade firmware.  From there you can upgrade both the tape drive & the library. Please let us know if you have any other questions.
Best,  Due to a broken drive on our TL4000 tapelibrary, dell support proposed to do a firmware upgrade hoping the error will be resolved by forcing the drive and library to reinvestigate eachother. When looking trough the downloads, I only found firmware upgrades for redhat or windows servers. Can you please tell me if (and how) it is possible to do the firmware upgrade using ubuntu? I Hope you guys can help me Kind regards Hannes De Bondt
Firmware upgrade TL4000 from ubuntu