yum upgrade v anaconda upgrade differences

Seth Vidal skvidal at fedoraproject.org
Sun May 17 14:07:18 UTC 2009



On Sun, 17 May 2009, David Timms wrote:

> On the yum list a question was asked which intrigued me:
> Why can anaconda manage to upgrade a system, when yum upgrade can't.
>
> The postulation was that anaconda is cheating (ie running --nodeps installs). 
> This would allow it to complete an upgrade where dependencies lead to 
> unavailable packages that are not on the dvd, but are in the complete Fedora, 
> and or non- fedora repositories, that are not available at upgrade time.
>
> Is that why it can work ?
> Or what are essential differences between an anaconda upgrade and yum upgrade 
> ?

anaconda is also running outside of the system you're trying to update - 
it doesn't have to worry about making its own environment entirely 
unusable. So it can do things like --nodeps w/o a concern for not being 
able to complete the transaction.

Finally anaconda uses a whiteout/blacklist info to be able to force 
certain things out of the transaction. preupgrade uses those, now, via a 
yum plugin.

-sv




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