I’ve got a personal server at home, onto which I’ve installed openSUSE 11.4 64-bit in server (text) mode. After installation I ran the command ‘zypper up’ as root to fetch the latest updates. Once I got the list of updates required and chose to continue, I noticed that for a lot of the packages that were being retrieved (possibly all of them, I’m not sure), there was also a so-called delta being retrieved and applied before the main installation of that particular update. What is this for? Is it some kind of pre-installation package required to prepare for an upgrade of an existing package, or is it something else?
> Once I got the list of
> updates required and chose to continue, I noticed that for a lot of the
> packages that were being retrieved (possibly all of them, I’m not sure),
> there was also a so-called delta being retrieved and applied before the
> main installation of that particular update. What is this for?
For updates, actually for patches, it is possible to download the full
updated package, or the corresponding delta, which contains only the
changes and is much smaller and faster to download. If zypper then fails
when trying to use it, it will switch to download the full package.
The rpm manual explains the details.
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Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
I see, so a delta saves on bandwidth by allowing you to only download the exact amount required for the update of a package? OK, but I also noticed that even after a delta was applied during the update retrieval phase, it then still continues with an ‘installation’ afterwards. What’s the difference between ‘applying a delta’ and ‘installing’ an update, or are they pretty much the same thing?
> I see, so a delta saves on bandwidth by allowing you to only download
> the exact amount required for the update of a package? OK, but I also
> noticed that even after a delta was applied during the update retrieval
> phase, it then still continues with an ‘installation’ afterwards.
> What’s the difference between ‘applying a delta’ and ‘installing’ an
> update, or are they pretty much the same thing?
As I said, the man page explains it.
It has to reconstruct the full package from the little it downloads, then
install it. Two phases.
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Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)