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wikipedia-en or wikipedia-zh

Info

Theophilus Benson*, Aditya Akella*, David A. Maltz+
*University of Wisconsin, Madison
+ Microsoft Research

IMC 2010 pdfppt

Insights Gained

• 75% of traffic stays within a rack (Clouds)
  • Applications are not uniformly placed
• Half packets are small (< 200B)
  • Keep alive integral in application design
• At most 25% of core links highly utilized
  • Effective routing algorithm to reduce utilization
  • Load balance across paths and migrate VMs
• Questioned popular assumptions
  • Do we need more bisection? No
  • Is centralization feasible? Yes

Looking Forward

• Currently 2 DC networks: data & storage
  • What is the impact of convergence?
• Public cloud data centers
  • What is the impact of random VM placement?
• Current work is network centric
  • What role does application play?

I use “github” to mange the code and “gitcafe” to backup, so I need to push the change of code to multiple git repositories simultaneously.(actually, the id on “github” and “gitcafe” are different)

1, clone the repositories for “github”;

2, change the configuration  .git/config, make it like:

[remote “web”]

         fetch = +refs/heads/*:refs/remotes/origin/*

         url = https://github.com/your-id/eg0.git

         url = git@gitcafe.com:your-id/eg1.git

         url = ssh://other.exaple.org/your-id/eg2.git

[branch “master”]

         remote = web

3, use git push web to pushing change to multiple git repositories

when “git push” , I get the error 

! [rejected]        master -> master (non-fast-forward)

error: failed to push some refs to ‘git@gitcafe.com:your-id/eg1.git’

To prevent you from losing history, non-fast-forward updates were rejected

Merge the remote changes (e.g. 'git pull’) before pushing again.  See the

'Note about fast-forwards’ section of 'git push –help’ for details.

so , use 

git remote add ….

to add the repository then pull down and merge into the master,

finally, “git push web” successfully.

refrence:

http://stackoverflow.com/questions/849308/pull-push-from-multiple-remote-locations

http://jeetworks.org/node/22

http://blog.csdn.net/mci2004/article/details/7763399

http://www.lingavin.com/post-49.html

software defined network , openstack software defined data center, the api-driven cloud

I installed kvm on a ubuntu 12.04 server which does not have x server.

When starting an existing virtual machine(file ended with .wmdk), I get error message:

Could not initialize SDL(No available video device) - exiting

add the parameters

-vga std -k en-us -vnc :1

at the end of the cmd may avoid this error.