I'm not sure if this is the right place to post this, but I'll give it a try and I'm sure our moderators will correct me if I'm wrong.

I have a 4G USB memory stick. I want to use this as my file system, instead of the standard, rotating disc. I have tried DSL and Knoppix on it, DSL by loading as per the instructions on the DSL page, Knoppix as a regular instal, just like I was installing to a real disk (the stick was recognized by the install prog as mass storage, so that went easy)

I want to use the system as a server (a very small, mobile OpenSwan gateway, as it happens, but that is not particularly relevant). While I can configure the files and get the apps and daemons running, I can't write the configs permanently to the stick. It seems I either get:
* a refusal to write a read-only system when editing files (DSL);
* when shutting down, the RAMdisk that was created does not get written back to the stick, so the next time I boot, there is just the vanilla stick (Knoppix).

Any suggestions on how to make the stick behave exactly as REAL R/W storage?

Have you looked at a solution like Feather Linux?

Or have I misunderstood your question?

Alex