Just a FYI that, as another member has noticed, I have created a presto repository for CentOS 5 updates (i386 only at the moment).
A presto repository allows you to download the differences between rpms rather than the full rpms when updating.

To set up yum-presto on your CentOS 5 box, run the following commands:

# cd /etc/yum.repos.d
# wget http://www.lesbg.com/jdieter/presto/presto-centos.repo
# yum install yum-presto

You will then need to edit /etc/yum.repos.d/CentOS-Base.repo which will have the following section:

[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

and change it to look like this:

[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
deltaurl=http://www.lesbg.com/jdieter/updates/centos$releasever/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5

Hope someone finds this useful.

Jonathan

This is very cool. Can you give us any of your personal pros/cons for what you have seen with presto so far.

Pros:
* Small updates. A normal kernel update is about 2 MB versus 16 MB for the full rpm. Normally, the larger the package, the better compression ratio you'll get. I think I'm averaging 80% savings for FC6 updates.
* Easy fail-over. If for any reason the deltarpm can't be reconstructed into the full rpm, yum goes ahead and downloads the full one.

Cons:
* It's still in beta. I've been using it on my FC6 system for a few months and on my CentOS systems for a couple of weeks now without any major problems, but there are still the occasional small bugs that pop up.

If you do run into problems, let me know and I'll fix it. While you're waiting, you can run yum with the --disablepresto switch to disable it and get normal yum behavior.

Not sure if that's what you're asking, but there it is.

Just a quick heads up that we've had to move to a new server. If you want to use yum-presto with CentOS 5, use:
deltaurl=http://lesloueizeh.com/centos5/i386/updates

Quote:

I'll say :)

One of the major gripes with RPM updates has to be downloading the whole package for a 1KB patch to fix some security issue. When applied to large packages (OpenOffice comes to mind), and over multiple servers/workstations, the bandwidth savings soon add up.

Of course once you have more than a few machines to maintain, one normally only downloads updates once and distributes them locally from a central location (well, at least that's what I do), but this is a very neat solution.

If you are interested in deltarpm and would like to contribute, please join the centos-devel mailing list:

http://lists.centos.org/pipermail/centos-devel/2007-September/003831.html

Akemi