What is qfs file?

I’m working with a board support package from Ampro. They send me two files with the bsp - lb700.ifs and lb700.qfs. I know how to create and install an ifs file, but I cannot find anything about a qfs file - does anyone know what this is, what it does, how to make one?


The qfs is a qnx4 filesystem image. You can mount it under Neutrino like a partition…

mount -tqnx4 lb700.qfs /lb700

Yes, I did discover that it is mounted - how is it different from an ifs? Do I need both an ifs and a qfs? How does one go about making a qfs?

ifs stands for Image File System. The name is a bit misleading, since although there is a filesystem component to it (the /proc/boot filesystem), it really is much more image than filesystem.

A qfs (Qnx File System), is exactly what most people expect when talking about a filesystem; that is, it is an on disk structure that organizes data into files (and nothing else).

That depends on the application. If you have (lets say) a hard real-time app that consists of a set of fixed processes that do not require any persistant storage, then an ifs alone is probably all you need (i.e. you don’t need a filesystem at all).

If you require persistant storage of any significant quantity then you’ll probably want a filesystem of some sort. QNX supports several different filesystems. The .qfs extension is purely a convention, and usually refers to a “QNX4” filesystem.

One simple way to make a qfs is to copy a partition from an existing device (e.g. “cp /dev/hd1t79 /tmp/foo.qfs”).

I Think I’m starting to understand… Does that mean that an IFS cannot be edited? I built a system using mkifs (actually from momentics…) then I loaded it onto my compact flash card on the target (which has both ifs and qfs on it). I booted the system and then edited the net.cfg file which I had included on the ifs. The changes I made stuck , so were those saved in the ifs or in the qfs?

I think what you mean is “that an ifs cannot be persisted”.

The answer to that is typically yes. The /proc/boot filesystem can, however, be “editted” (if by editted you mean files created/destroyed/re-created).

Probably. At some point (in your .script ?) you most likely started a driver for the compact flash card, and then mounted a filesystem present on the compact flash, into your namespace.

You should have a build file that you can use with mkifs to regenerate the ifs file.