[CentOS-devel] RFC: Performance tuning of the Vagrant images

[Laurentiu Pancescu]

Hello everyone,

I would like to ask for your feedback about tuning the official CentOS 
images for Vagrant.  The good news: the next release will probably 
provide Vagrant images for both CentOS 6 and 7, not just 7 as until now.

Deltarpm allows yum to download just binary diffs for the already 
installed packages and rebuild the rpms locally, thus decreasing the 
used bandwidth.  However, this is quite CPU and I/O intensive, and 
significantly slower than just downloading the full packages (at least 
for users on any sort of broadband connection).  Deltarpm can be useful 
for users in development countries, which do not always have access to 
unmetered broadband, while someone hosting many VM instances on the same 
server, like a VPS provider, might want to avoid the extra I/O load 
(especially on mechanical hard-disks).  Deltarpm is already part of the 
CentOS 7 images since May 2015 - should we keep it or remove it?

Tuned, a daemon that can adjust system parameters based on the workload 
(it comes with a number of profiles, optimized for different 
situations), is preinstalled in CentOS 7, and can significantly improve 
performance and/or reduce load.  Tuned can also be installed in CentOS 
6, and it would increase the size of the Vagrant image with just 291kB, 
since its prerequisites are already installed.  Should we add it to 
CentOS 6?  If you are not familiar with tuned, the following links might 
be helpful:

http://servicesblog.redhat.com/2012/04/16/tuning-your-system-with-tuned/
http://www.slideshare.net/IamFedora/tuned


Thanks in advance,
Laurențiu