I'm just experimenting with an ASUS wl-500g Deluxe router.

It can use an external USB stick, and according to UsbStorageHowto on http://wiki.openwrt.org/UsbStorageHowto - it is possible to boot from the USB stick.

Unfortunately, "4.2. How do I boot from the USB device" describes how to boot from an ext3-formatted USB device.

As originally openwrt uses jffs2 as its primary image, I thought it would be best to use jffs2 on an external USB device (to gain some space).

How can I format an external USB device with jffs2 filesystem (and use it as root as a next step)?

I tried playing with mkfs.jffs2 on my PC, but I'm not sure how to create a filesystem and put it for example on a 256 MB USB-stick.

Any ideas?

JFFS2 for Journaling Flash Filesystem 2, as its name is self-explanatory, is for flash memory. So please use an appropriate filesystem

In that case, I suppose this trick might work:

1) format USB-stick with some (ext2, ext3, fat?) filesystem,
2) create a jffs2 image on your PC, the size of which would match the size of the USB-stick
3) put the USB stick to the router, and mount the image

In that case the "init" script described on UsbStorageHowto would have to be modified a bit to mount such an image first.

Is my thinking correct?

Hmm, I guess that the thinking is correct, but it would be impossible to do so on these tiny routers.

It appears that to mount a jffs2 image that is 256 MB big you would need 256 MBs of RAM...

Hi there,
I use OpenWGT for my WGT634U ^^,
and this thingy can actually boot from the usb stick, which is kinda cool!
^.^
Ok, I have formated my 128Mb Stick with ext3,
which works perfectly.

How they do that, I dunno, check their source?

Nico

Yeah I know, booting form a ext3-formatted USB stick is easy, just read the documentation

What I want to do is to squeeze some more data from a USB-stick and to use a compressed filesystem.

Unfortunately, there is only one filesystem taht supports compression in Linux: jffs2.

There is also "compFUSEd" - http://parallel.vub.ac.be/~johan/compFUSEd/ - with that you can use compression on any filesystem.

It uses FUSE, and there is a fuse module for openwrt - so I wonder if compFUSEd could be built for openwrt?