DNF vs. YUM

[Justin Brown]

On Thu, Mar 13, 2014 at 6:44 PM, Sam Varshavchik <mrsam at courier-mta.com> wrote:
> Jan Zelený writes:
>
>> On 13. 3. 2014 at 13:41:48, Tethys wrote:
>> > On Thu, Mar 13, 2014 at 1:35 PM, Mark Haney
>> <mhaney at practichem.com> wrote:
>> > > So, let me get this straight, DNF doesn't check the (online?) repo
>> > > metadata when I call 'sudo dnf update'?  That's how I'm reading this.
>> > >
>> > >  If that's true, why the devil not?
>> >
>> > At a guess, for marketing reasons. People see apt as being quicker
>> > than yum, and in a large part that's because it doesn't update
>> > metadata where yum does, so people are comparing two different things.
>> > I believe that not checking metadata is retarded and I don't think
>> > we're right in moving to the same architecture. But it wouldn't
>> > surprise me if that's the rationale.
>>
>> And you are absolutely correct.
>>
>> The metadata are quite large and downloading them every single time is
>> time consuming. There is usually no harm in getting the updates a few days
>> later and if you really want to get the very latest updates, you still
>> have
>> options how to achieve that - either change the time period for how long
>> the
>> MD should be cached or run dnf clean * before you run the update.

Don't do that.


> And that's exactly how it's going to end up playing out, I'll bet anything
> on this. Most people will simply clear the cache explicitly, before they run
> dnf. Or, they'll put it in a crontab to run every night.

Perhaps consulting the dnf documentation is a better option than
pursuing either of these silly behaviors.

man dnf.conf

       metadata_expire
              time in seconds

              The period after which the remote repository is checked
for metadata update and in the positive case the local metadata cache
is updated. The default corresponds to 48 hours.

So your cron job every night could be more simply achieved by setting
this to 86400, and your `dnf clean all` before every dnf option could
be automatically achieved by setting it to 0. Additionally if the need
arises to use intentionally use cache (even if expired), -C can be
used with dnf.

There's nothing to complain about here because you're given total
control over this behavior.