Filesystem classes

Updated: May 06, 2022

The many filesystems available can be categorized into the following classes:

Image
A special filesystem that presents the modules in the image and is always present. Note that the procnto process automatically provides an image filesystem and a RAM filesystem.
Block
Traditional filesystems that operate on block devices like hard disks and DVD drives. This includes the Power-Safe filesystem, DOS, and Universal Disk Format filesystems.
Flash
Nonblock-oriented filesystems designed explicitly for the characteristics of flash memory devices. For NOR devices, use the FFS3 filesystem; for NAND, use ETFS.
Network
Filesystems that provide network file access to the filesystems on remote host computers. This includes the NFS and CIFS (SMB) filesystems.
Pass-through
Filesystems that sit in front of another filesystem and manipulate files that are in the underlying filesystem. This includes the Inflator filesystem, which uncompresses files that were previously compressed (using the deflate utility).
Note: Running more than one pass-through filesystem or resource manager on overlapping pathname spaces might cause deadlocks.
Virtual
Filesystems in which the files or directories aren't necessarily tied directly to the underlying media, perhaps being manufactured on-demand. This includes the /proc filesystem; see Controlling processes via the /proc filesystem in the Processes chapter of the QNX Neutrino Programmer's Guide.