7
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?
Lazer
Posted 2010-08-01T19:13:50.353
Reputation: 13 841
In yum, what is presto?
Answers
9
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.)
Apache
Posted 2010-08-01T19:13:50.353
Reputation: 14 755
beaten by 20 seconds >.< – Sathyajith Bhat – 2010-08-01T19:33:07.347
Sorry man... :D – Apache – 2010-08-01T19:33:46.630
1The extra disk IO and CPU load is negligible compared to the bandwidth saving. – Zaz – 2010-08-02T09:19:13.527
Indeed. I just wanted to say you pay with those. Like some admin said: "Currently, bandwidth is cheaper". That's why some smaller distro won't ship this since they dont have enough resource on the servers. – Apache – 2010-08-02T10:27:42.233
3
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.
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.
Zaz
Posted 2010-08-01T19:13:50.353
Reputation: 1 843
Delta-RPM, not deb. Fedora uses RPM. – Sathyajith Bhat – 2010-08-01T19:44:15.823
@Sathya: Whoops, fixed now. – Zaz – 2010-08-01T22:49:52.240
2
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:
Sathyajith Bhat
Posted 2010-08-01T19:13:50.353
Reputation: 58 436
3Only in a geek community could you ask a question like this without people questioning your sanity. ;-) I have no idea what you are asking, but my first instinct was to open up the question so I could find out what yum and presto are. Sure enough there are several excellent answers with links to explain both. – Wayne Johnston – 2010-08-02T00:25:12.603