df says the disk is full, du says half of it is free, and deleting the log did not help. Explain it.

Two commands disagreeing is the diagnosis, not the mystery. A deleted file with an open handle is invisible to du and fully charged by df, and rm made it worse rather than better.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.