Virtuozzo File System (VZFS)
VZFS is a file system that allows to share common files among multiple VPS Hostings without sacrificing flexibility. It is possible for VPS Hosting users to modify, update, replace, and delete shared files. When a user modifies a shared file, VZFS creates a private copy of the file transparently for the user. Thus, the modifications do not affect the other users of the file. Main benefits of VZFS are the following:
1) It saves memory required for executables and libraries. A typical VPS Hosting running a simple web website hosting might consume around 20–30 MBytes of RAM just for executable images. Sharing this
memory improves scalability and total system performance;
2) It saves disk space. A typical Linux server installation occupies several hundred MBytes of disk space. Sharing the files allows you to save up to 90% of disk space;
3) VZFS does not require having different physical partitions for different VPS Hostings or creating a special “file system in a file” setup for a VPS Hosting. This significantly simplifies disk administration;
4) Disk quota enables the administrator to limit disk resources available to a VPS Hosting on-the-fly, in the same manner as the standard disk quota system works on a per-user basis. Disk quota for users and groups inside VPS Hostings is also supported.