To remove cached metadata and transaction use 'dnf system-upgrade
The downloaded packages were saved in cache until the next successful
You can remove cached packages by executing 'dnf clean packages'.
My sense is that those two dnf commands are things the sys.admin. does
if something goes wrong and he has to back-track (or start over). Am I
correct, or should I do those? By the way, the dnf man page makes no
mention of a system-upgrade command.
And who is the "sys.admin" and does the "sys.admin"-tasks on your box
according to this link:
there is no explanation of 'dnf system-upgrade clean' !
so what it really does I don't know, but (I guess) it mainly removes stuff you
don't need anymore !
stuff that was only necessary for the upgrade process/task. I guess mainly packages which
are installed or somewhat better: the contents of these packages is copied to their target
directories (see below).
for 'dnf clean packages'
the command cleans under /var/cache/dnf/ and this directory is filled/updated (again !!!)
during any run of "sudo dnf upgrade"
so if you clean there there is no harm !
a try of an explanation:
lets say you want upgrade/install a package and let's say it's name is
let's assume it contains mainly configuration files for the target directory /etc
if you do "dnf upgrade" or "dnf install config.rpm" mainly two tasks
a) config.rpm is downloaded (!) to /var/cache/dnf
b) config.rpm is installed (!), what mainly means it's contents is "copied"
to it's target directory /etc
after both tasks there is no need to keep the packages "config.rpm" under
after installation it has done it's purpose !
with other packages it works analogous -maybe other target directories are involved-