resource sharing

In Virtuozzo set a goal to virtual environment does not have any information about the "iron" server configuration. All pseudo-directory / dev / remain, but an appeal to him is transferred to the underlying OS, and only then on the driver shared resources. Problems can arise if the application requires direct access to the equipment, but most of the tested applications did not require such access, it is a well-worked in a virtual environment.

A more complicated situation with the file system / proc, which contains background information about the kernel, the processes and the periphery. It is observed the same rule of the whole system is available, and specific equipment such as bus, memory and processor - no. In some cases of pseudo-directory of the application can obtain information about a single virtual environment, and in some - on the server as a whole. In particular, such a distinction may be important to assess the workload of the processor: for some programs is sufficient to give information about the virtual environment, and some - the total load on the CPU. The developers wanted to ensure that existing applications without recompiling.

Inside the virtual server does not have direct access to the network interface. All operations are performed with the network using standard kernel functions, implementation of which changed significantly in Virtuozzo. Each virtual environment is allocated a certain guaranteed bandwidth of the external canal, and interoperability with other media on the same server within the concept of a virtual network. And if necessary, can accommodate a variety of IP-numbering separate IP-address on every Wednesday, the total IP-address with the division of DNS-name or address translation within the virtual network. Such an organization of the network is necessary for the application to a virtual environment could not peek data transmission over the network by other virtual environments, addressing this directly to the driver Ethernet. These functions are implemented using a special layer in the kernel, which gives each its own separate environment, a virtual network interface API, similar to most network interface on Linux.

Virtualization drives software is based on changes in the root directory chroot. Each virtual environment is allocated its own subdirectory, which contains all the data a separate environment. The administrator selects a mount point and a common configuration file structure, and applications within the virtual environment does not have direct access to the disks, so the functions they mount the new drives are not available. Mount operation must be the administrator of the Virtuozzo host operating system. If necessary, a separate environment can provide access to one of the disks directly, but in the standard configuration Virtuozzo is not provided.

Separation of computer resources - memory, CPU time, network access, and others - built on the principle of minimum guaranteed level. If the server is too busy, the virtual environment can get additional resources. However, for storage are other algorithms based on the restriction on the amount of stored data. If the resource is shared (as is done for the joint use of libraries), then occupied by them operational and disk space is divided evenly among users.