In yum, what is presto?

When I do a yum install or a yum update, sometimes I get this

Loaded plugins: presto, refresh-packagekit

telling me that the packages are being updated.

What is presto?

Solution 1:

Presto makes yum download only the delta. The changes. It downloads them and apply them on the existing data, thus it saves a lot of bandwidth. (You pay with Disk IO and CPU load instead.)

It is a really good thing for developing countries, people with mobile internet and so on.

ps.: OpenSUSE been using this for a long time. If I remember clearly they were the first RPM based delta users, but fixme, I'm not sure about this. (openSUSE downloads delta, apply, install package. On Fedora: Download all delta, apply them, install them all.)

http://fedoraproject.org/wiki/Releases/FeaturePresto

Solution 2:

It adds support for delta-RPMs which use a delta-transfer algorithm to save time downloading. Basically, presto won't download the entire package, only the changes since the last version.

Fedora Wiki:

The presto plugin for yum adds support for downloading deltarpms and using them to generate new packages. If user enables this plugin, it will make a substantial dent in the amount of data having to be downloaded for updates.

Solution 3:

Presto is a plugin which enables Delta RPM support in yum. Basically, deltaRPM creates a new RPM based on the diffs of the new and previous version - saving on bandwidth and time required to download, since only the "changed" bits will be downloaded, instead of the full monolithic package.

More details:

• Fedora Features/Presto

• Delta RPM FreshMeat page