FreeBSD jail is an operating system-level virtualization mechanism that we use in the VDSmanager software product. FreeBSD jail facility provides a light-weight form of virtualization and included in the FreeBSD 4 distribution and later versions.
Our development team did a great job at modifying the FreeBSD kernel. They improved the virtualization support significantly.
The modification to the kernel was made:
- added support for CPU limit per Virtual Server.
- virtual memory limits. Our system terminates processes that overrun the RAM memory limits.
- swap settings – limits, usage, statistics.
- template-based FileSystem implementation.
- disk quota support.
- per VPS process limit for the number of processes.
- limit on file descriptors that any one process may open.
- multiple IP support on one network interface.
- sysctl parameters – added new ones, hidden those not required.
- ability to set and manage limits with a click of a mouse.
- personal ipfw firewall configuration.
- SssV support.
RAM Memory usage pattern
RAM’s unique distribution method implemented in VDSmanager virtualization technology allows substantial memory saving. These significant memory savings relates to a read-only memory used by various server software.
As you know, the processes running on the system have sections of memory read-only. So in theory any read-only section can be shared across processes. For example, one MySQL database running several times will use a single physical read-only memory section for all the active mysqld processes.
VDSmanager demonstrates substantial RAM savings not only between Virtual Machines running same processes using a single read-only section, but even across Web Servers running disparate workloads
Let’s consider a specific example of the method. Mysqld read-only section is about 3 MB. Imagine, you have 100 Virtual Machines running on your server. Each web server runs a MySQL server (one mysqld process per server). Thus, we will need 300 MB RAM (3 * 100 = 300).
See how we can reduce memory usage by nearly 98%. VDSmanager technology allows the ability of using 3 MB RAM ONLY for all Virtual Servers, and provides 297 MB of memory savings
Template-based FileSystem
In VDSmanager, a modified unionfs file-system is used to implement a template-based FileSystem for Virtual Servers.
VPS FileSystem is based on particular disk template that includes all required software files. When a VPS account is created, all the files in the template directory are not copied to the new VPS home directory. There will be a union of the template files and private files of VPS.
This method has a number of advantages:
- The FileSystem content is displayed in a block.
- With such files organization, it is advantageous to provide a wide range of pre-installed software that will not take up any memory.
- Administrator can manage VPS FileSystem. Modified files are copied from the server public directory into the Private Files Directory.
Advantages for Hosting Providers:
- Ability to create VPS accounts on a fly.
- Significant saving of disk space.
- Easy updates for all the preinstalled software (Update the VPS software based on the template by modifying the template).
VDSmanager distribution comes with a selection of disk templates. The developers of the included software provide regular update for their products. We offer Hosting providers to enable auto-update option that allows to update all of the software products or just the selected items.
VDSmanager Virtualization Advantages
VDSmanager virtualization technology is the way to save system resources and money and increase a Virtual Server efficiency.
By reducing the usage of system resources and providing unique FileSystem, VDSmanager-FreeBSD is able to improve the way you run your web hosting business. Using our software, you will get:
- Much more disk space available to you VPS. Again, this allows more efficient use of server resources.
- Automatic Update settings for your disk templates. This option allows you to provide your customers with services similar to the Managed VPS service. Server Administrator will not have to monitor the server software updates.
VDSmanager Virtualization Technology has been successfully tested and proved to be the best virtualization solution for use on the FreeBSD operating system. Many years of experience in using the VDSmanager software and providing VPS Hosting services, demonstrate the assurance of the software flexibility, stability and reliability.
