Editing Virtual file system (section)

==Single-file virtual file systems==
Sometimes Virtual File System refers to a file or a group of files (not necessarily inside a concrete file system) that acts as a manageable container which should provide the functionality of a concrete file system through the usage of software. Examples of such containers are CBFS Storage or a [[Disk image#Virtualization|single-file virtual file system]] in an emulator like [[PCTask]] or so-called [[WinUAE]], Oracle's [[VirtualBox]], Microsoft's [[Virtual PC]], [[VMware]].

The primary benefit for this type of file system is that it is centralized and easy to remove. A single-file virtual file system may include all the basic features expected of any file system (virtual or otherwise), but access to the internal structure of these file systems is often limited to programs specifically written to make use of the single-file virtual file system (instead of implementation through a driver allowing universal access). Another major drawback is that performance is relatively low when compared to other virtual file systems. Low performance is mostly due to the cost of shuffling virtual files when data is written or deleted from the virtual file system.

===Implementation of single-file virtual filesystems===
Direct examples of single-file virtual file systems include emulators, such as PCTask and WinUAE, which encapsulate not only the filesystem data but also emulated disk layout. This makes it easy to treat an OS installation like any other piece of software—transferring it with removable media or over the network.

====PCTask====
The [[Amiga]] emulator [[PCTask]] emulated an [[Intel]] PC [[Intel 8088|8088]] based machine clocked at 4.77[[MHz]] (and later an [[80486]]SX clocked at 25&nbsp;MHz). Users of PCTask could create a file of large size on the Amiga filesystem, and this file would be virtually accessed from the emulator as if it were a real PC Hard Disk. The file could be formatted with the FAT16 filesystem to store normal MS-DOS or Windows files.{{Ref label|PC Drives|1}}{{Ref label|PCTask|2}}

====WinUAE====
The [[UAE (emulator)|UAE]] for [[Microsoft Windows|Windows]], [[WinUAE]], allows for large single files on Windows to be treated as Amiga file systems. In WinUAE this file is called a ''hardfile''.{{Ref label|WinUAE Hardfile|3}}

UAE could also treat a directory on the host filesystem ([[Microsoft Windows|Windows]], [[Linux]], [[macOS]], [[AmigaOS]]) as an Amiga filesystem.{{Ref label|WinUAE Add Directory|4}}