Callback File System™

Callback File System lets you create virtual file systems and disks that meet your requirements, giving you full control over your data.

Created by: EldoS Corporation

Virtual File System (VFS) is a filesystem that doesn't reside on a partition of a "physical" disk. VFS hides the location (and format) of the actual data storage from the system and the applications.

The actual data that make a filesystem can be located in files spread across the local disks or in applicaiton resources or in memory or somewhere at a remote location. Moreover, using a virtual filesystem you can modify the data being read from or written to the virtual filesystem and such modifications are completely transparent for the applications. At the same time, the operating system and the applications "see" the virtual disk as a local disk device.

Virtual filesystem can be indispensable in various scenarios. The examples of use are:

• document management systems, which keep document versions in the centralized database and must keep control over the data which is saved and loaded;
• applications which provide remotely-located disks to the local user (various *FTPDrive applications, WebDAV systems etc);
• applications which let the users manage the remote data storages (eg GMail access application that lets the users view e-mail as files);
• porting of applications, that use FUSE software, from Linux;
• and more ...

Creation of virtual filesystems in modern operating systems like Windows is possible due to existence of the model of low-level (kernel-mode) drivers. Development of such driver, that requires deep knowledge of the operating system internals, is a challenging task even for experienced developers. Besides complexity, driver development is a very time-consuming process.

Callback File System is an SDK (Software Development Kit) which opens the way to create your own filesystems with little or no efforts. The product includes ready-to-deploy kernel-mode device driver and a user-mode API, which is used by your application. The driver creates a virtual disk with your filesystem and provide system-wide access to the disk. The API lets you manage the driver and the virtual disk from any Windows or .NET application.
With Callback File System you can run your filesystem code in user mode, letting the driver deal with complexities of the kernel mode.

Callback File System lets you create a filesystem, and if you need a slightly different functionality or a ready-to-deploy filesystem, you can take a look at other our products:

• Solid File System Driver Edition SDK. This product implements an industry-level filesystem with advanced features (such as access control, encryption, resizeable storage, advanced functions of SolFS itself) and also lets you create a virtual disk which you can store everywhere.
• CallbackDisk, which lets you create virtual drives and disks, format them to FAT or NTFS, and mount as if they were physical devices. CallbackDisk includes only the basic functionality, necessary to implement a virtual disk.
• CallbackFilter, which lets you monitor activity on existing file systems, control file and folder operations, modify files on-the-fly etc.

For technical information about Callback File System SDK please read Detailed Description.