[Yum] installing by group versus installing by individual packages

[James Antill]

"Robert P. J. Day" <rpjday at crashcourse.ca> writes:

>   trying to clarify a couple things regarding installing/removing
> by yum group on my fedora 19 system. first, what is the rationale
> behind "hidden" groups? what's the motivation that some groups
> (for the case i'm interested in, virtualization) not be user visible?

 The main idea with hidden is for things like "base", where it's
assumed the user doesn't need to see it. But even that might not be
true now we have groups as objects.

>   second, if i haven't installed the virtualization group, i can
> query it and i see:
>
> Group: Virtualization
>  Group-Id: virtualization
>  Description: These packages provide a virtualization environment.
>  Mandatory Packages:
>    +virt-install
>  Default Packages:
>    +libvirt
>     libvirt-daemon-kvm
>     qemu-kvm
>    +virt-manager
>    +virt-viewer
>  Optional Packages:
>    +guestfs-browser
>    +libguestfs-tools
>    +python-libguestfs
>    +virt-top
>
> that seems fairly straightforward -- i'm seeing what would happen
> if i installed that group. '+' means packages that would be
> installed, while no symbol represents packages that are already
> installed. and after i install by group, i get:

 Right.

> Group: Virtualization
>  Group-Id: virtualization
>  Description: These packages provide a virtualization environment.
>  Mandatory Packages:
>    =virt-install
>  Default Packages:
>    =libvirt
>     libvirt-daemon-kvm
>     qemu-kvm
>    =virt-manager
>    =virt-viewer
>  Optional Packages:
>    -guestfs-browser
>    -libguestfs-tools
>    -python-libguestfs
>    -virt-top
>
> where i assume '=' means that package was installed by that
> group install command, while '-' means not installed (optional).

 Yeh, although to clarify '=' is probably better off thought of as
meaning that the package belong to the group and would be removed
via. "group remove thisgroup"

>   however, if i had installed all those virtualization packages,
> not with a single group install command but by explicitly
> installing each package, i would have ended up with:
>
> Group: Virtualization
>  Group-Id: virtualization
>  Description: These packages provide a virtualization environment.
>  Mandatory Packages:
>     virt-install
>  Default Packages:
>     libvirt
>     libvirt-daemon-kvm
>     qemu-kvm
>     virt-manager
>     virt-viewer
>  Optional Packages:
>    +guestfs-browser
>    +libguestfs-tools
>    +python-libguestfs
>    +virt-top
>
> which would have had the same effect but, i'm guessing,
> from the perspective of yum, the virtualization group is
> *not* installed. so, for instance, i can't remove those
> packages using a "yum groupremove"; i would have to do it
> explicitly again. do i understand this vaguely correctly?

 Yeh, that's right. The other main difference here is that "group
update virtualization" does nothing (because the group isn't
installed). And with upgrade_group_objects_upgrade=true (no
config. but always true in F19 GA yum) "yum upgrade".

>   if there's a good explanation of this online, a URL would
> be dandy, thanks.

 The main documentation is in "man yum" / "man yum.conf" and there
might be some in the Fedora online documentation.

-- 
James Antill -- james at and.org