single-file file system?

single-file file system?

[Erez Zadok]

I have a need for a very simple f/s that supports only one file on a raw
device, starting from the beginning of the device and growing until possibly
its end.  The reason for this simple f/s is to minimize the overhead for
certain applications that don't need more than one large file, but cannot
use a raw device directly (i.e., they expect a f/s interface).  Do you know
of any f/s that does that for Linux?

Thanks,
Erez.

Re: single-file file system?

[Andi Kleen]

On Fri, Sep 24, 2004 at 04:26:13PM -0400, Erez Zadok wrote:
> I have a need for a very simple f/s that supports only one file on a raw
> device, starting from the beginning of the device and growing until possibly
> its end.  The reason for this simple f/s is to minimize the overhead for
> certain applications that don't need more than one large file, but cannot
> use a raw device directly (i.e., they expect a f/s interface).  Do you know
> of any f/s that does that for Linux?

iirc there was one long ago from Miquel van Smoorenburg for 2.4 (or maybe
2.2 i don't remember). But if you want it for 2.6 it would be probably
easier to just rewrite it.

-Andi

Re: single-file file system?

[Christoph Hellwig]

On Fri, Sep 24, 2004 at 04:26:13PM -0400, Erez Zadok wrote:
> I have a need for a very simple f/s that supports only one file on a raw
> device, starting from the beginning of the device and growing until possibly
> its end.  The reason for this simple f/s is to minimize the overhead for
> certain applications that don't need more than one large file, but cannot
> use a raw device directly (i.e., they expect a f/s interface).  Do you know
> of any f/s that does that for Linux?

We actually have a filesystem that represents blockdevices as single big file
in fs/block_dev.c.  It's just not mountable.