#dbx

fwupdmgr refuses the UEFI dbx (Secure Boot revocation list) update with "does not currently allow updates: Not enough efivarfs space, requested 30,7 kB and got 20,0 kB". The NVRAM variable store is full of legitimate, fragmented Secure Boot key data — the new dbx is larger than the free slot. Diagnose it safely with efivar/efibootmgr, understand why deleting boot entries or efivars does not help, and apply the proven fix: erase and restore Secure Boot keys to defaults in the BIOS, which repacks (defragments) the variable store. Tested on a Framework 16 AMD 7040 / Fedora 44, fwupd 2.1.5.