Skip to main content

OpenVZ VSwap


New RHEL6-based OpenVZ kernel has a new memory management model, which supersedes User beancounters. It is called VSwap.
Now you can set two primary parameters: physpages and swappages, while all the other beancounters become secondary.
  • physpages
This parameter limits the physical memory (RAM) available to processes inside a container.
The barrier is ignored, and the limit sets the limit.
Currently the user memory and the page cache are accounted into physpages.
  • swappages
This parameter limits the amount of swap space which can be used for processes inside a container.
The barrier is ignored, and the limit sets the limit.
The sum of physpages.limit and swappages.limit limits the maximum amount of allocated memory which can be used by a container. When physpages limit is reached, memory pages belonging to the container are pushed out to so called virtual swap (vswap). The difference between normal swap and vswap is that with vswap no actual disk I/O usually occurs. Instead, a container is artificially slowed down, to emulate the effect of the real swapping. Actual swap out occurs only if there is a global memory shortage on the system.


Labels:

Comments

Post a Comment

Popular posts from this blog

Feedly launches 'Feedly Cloud' sync platform, new web interface

Feedly, one of the leading Google Reader replacement services, announced major restructuring of its services today with a new cloud infrastructure and web interface. Posted on its official blog, Feedly unveiled what it calls "Feedly Cloud", a scalable infrastructure it says is ready to replace Google Reader. The new Feedly Cloud provides several benefits, the first of which is one-click import from Google Reader -- new users to the service can now simply pull everything over seamlessly from their Google account and start using Feedly right away. Existing users will simply have to make sure that they have the latest version of Feedly installed, and their accounts will be migrated to Feedly Cloud over the next few days. Additionally, the new service allowed Feedly to create a stand-alone web interface (found simply at cloud.feedly.com) that works in all major browsers without plugins or extensions. The transition to Feedly Cloud has another benefit, and that is the abilit...
Post a Comment
Read more

Google+ Rolls Out Restricted Communities for Corporate Users

Google this week rolled out a new Google+ security feature for organizations intended to help them keep certain conversations private from the larger Web. Much like Microsoft's Yammer, Google+ restricted communities will only allow access to approved employees. "Whether it's designs of your beta product or notes from your team off-site, anything you post will remain restricted to the organization," Google+ product manager Michael Cai wrote in a blog post. Community administrators can decide whether the site will remain open to everyone at the company, or kept private by invitation only. Google+ also allows for people outside of your domain — clients, agencies, business partners — to join the conversation.
Post a Comment
Read more