[packagekit] questions about documentation, clean cache, security only updates

[René Genz]

Hi,

thanks a lot for all your effort put into PackageKit. :)


I have some questions. I put them first and background information follows.
We are using Fedora 22 x86_64 and will upgrade to Fedora 24 x86_64.
Different desktop environments (Xfce, GNOME, KDE) are used.
Nvidia drivers from RPMFusion are in use.


question 1:
Where to find the full documentation of pkmon and pkcon?


In `man pkcon` and `man pkmon` you can read:
"The programs are documented fully on http://www.packagekit.org."

I cannot find the documents.



question 2:
How do I clean the cache at "/var/cache/PackageKit"?


As you know:
$ pkcon update --only-download

saves RPM files to:
/var/cache/PackageKit/${FEDORAVERSION}/metadata/${REPONAME}/packages/


On the other hand:
$ sudo dnf update --downloadonly -y

saves files to:
/var/cache/dnf/...

I can clean the cache of dnf manually with:
$ sudo dnf clean all

I could not find out how to clean the cache of pkcon.
$ sudo rm -rf /var/cache/PackageKit/${FEDORAVERSION}
seems to be too blunt to me.



question 3:
Is it possible to have:
a) apply only security updates (see dnf-automatic note below) and
b) automatic offline updates
with pkcon?

I can create a timer unit in systemd that triggers a service unit that would execute the commands for (a).
When a computer user reboots the computer the rest will happen automatically in offline mode.


In Fedora 22 I have been using dnf-automatic for updates. What I do like in dnf-automatic config file:
/etc/dnf/automatic.conf

you can define to download and apply only security updates with:
upgrade_type = security

(I want to avoid problems due to unnessary patches.)

The drivers from RPMFusion are omitted.
They miss the 'security update' information as far as I could find out.
Due to kernel updates sometimes kernel modules from the driver are not compatible anymore.
Hence I modified dnf-automatic.service. I added at the end:
ExecStart=/usr/bin/dnf update -y *nvidia*


dnf-automatic uses online updates.
By and large no major problem.
However, after one update I loged out and the display turned black with a blinking cursor.
The situation did not recover after several minutes.
The solution was: Ctrl+Alt+F2 ; log in as root ; reboot machine
As far as I remember the logs mentioned something about 'incompatible ABI'. On of the problems described here:
https://fedoraproject.org/wiki/Features/OfflineSystemUpdates

In order to avoid this problem in future I want to utilize offline updates in future.



question 4:
(related to question 3)
Should one abandon the notion of sticking to "security only" updates and apply all updates?



question 5:
When users leave their computer running for a long time (several months) offline updates will not help in deploy of updates.
Asking for more frequent reboots is one solution.
Another is online updates with dnf-automatic and risking running into problems again.
I am unsure. Any opinions?

-- 
Kind regards,
René