Currently, there is no way to restore the OS to it's factory condition without a re-flash. I think it would have been relatively easy to implement this in the OS. They should have put the OS image on the mmc2 and do all writes to mmc1 with a write filter on the OS. That way, all one has to do to return the device to a factory state is to delete all files on mmc1. I would think that this would also lead to a performance increase since you can do reads & writes to 2 different cards concurrently. Also, you would have full use of the mmc1 space for applications.

This is similar to how Windows Mobile devices work. The OS image is in ROM and all writes are done to RAM through a write filter. Once you do a "hard reset", all RAM is deleted and the device returns to it's factory state. However, with that comes the problem of constantly powering the device or losing everything in RAM, which we would not have with n8x0 since writes would be on the mmc1 card.

Does anyone think this is a good idea or should be considered for implementation?

Been reading the leaks of the upcoming N900. I think Maemo 5 should have a OS Hard Reset option similar to the one I outlined, Since from what I can gather, the N900 is going to be marketed as a Phone/MID. One would need a way to return the product to a factory state (especially on a phone type device), in case of OS corruption, viruses, misconfiguration, etc,

Are you finding you need to do this often?

I try out a lot of applications and I like starting from a clean system now and again. I'm used to doing this with Windows Mobile devices, but reflashing the Nokia's seem cumbersome and I don't know what effect it's going to have on flash life.

What you describe could be easily achieved by using unionfs. It is wasteful of flash (since you might have a lot of the read only system) overlayed. This is not how UNIX people think (frequent needs for resetting system to original state), so it was not implemented. Maybe on a phone it makes more sense, so I won't be surprised if this feature is in Maemo's future.

What would be the downside of such a system? I don't understand your point about flash waste. Got OS in one partition, apps & changes in another. If you update the system files (ROM), then yes, but that should be minimal. What do you do when the system gets bloated in Linux? In Windows (mobile & desktop) you get registry bloat, dll's, directories, etc. left over from programs. What about Linux system corruption or applications that stop working even with a reinstall, viruses, etc.

We don't actually have all the problems you describe. Persistent configuration problems (app does not work after install) is corrected by actually finding out what is wrong. In the worst case, I delete this application's configuration, not the whole system. Gconf bloat is not really an issue, since in a good storage system, the size (or amount of stuff stored) should not have noticeable effect on performance. If a system gets corrupted on disk, the package system can usually find and correct the corrupted files. Applications usually use the system version of libraries (and certainly don't install their own versions). This has other problems (compatibility issues) but reduces the "need to format" issues.

About the downside, you might want to replace a large part of the system. In a usual Linux distribution almost every important system package gets updated occasionally.