A user accidentally deleted a critical file. A technician tries to restore it from tape backup but receives an error that the file does not exist on the tape. What should the technician do first?

The best course of action for the technician in this scenario is to verify that the correct tape is in the tape drive. This is crucial because restoring a file from a backup depends on having the right tape that contains the desired backup data. If the technician attempts to restore from the wrong tape, it will naturally result in the error indicating that the file does not exist, as the file would not be stored on that particular tape.

By confirming that the correct tape is loaded, the technician ensures that they are accessing the backup that potentially contains the deleted file. This step acts as an initial troubleshooting measure before moving onto more complex or time-consuming actions like re-indexing the tape library or updating firmware. Both of those can be necessary later on if there is indeed an issue with the tape library or hardware, but verifying the tape is a straightforward and critical first step that can save time and resources.