For review: NAND out of space patch.

[Erik Garrison]

On Tue, Jul 22, 2008 at 04:05:33PM -0400, C. Scott Ananian wrote:
> We should distinguish at least three solution spaces:
>  a) UY's solution, based on a small patch to 656
>  b) A solution to include in 8.2
>  c) The "real" solution, in case there are limits to what we can do for 8.2.
> 
> cjb's patch is primarily for (a), with applications to (b) and
> *perhaps* as a fail-safe for (c) (if we can detect the condition in
> which the fail safe needs to be employed with any sort of
> reliability).
> 
> For the record, I oppose the unionfs solution for the "real fix",
> because it impairs overall reliability: it works for the "first boot
> in completely full disk" case, but doesn't work for the "almost full"
> case or for the "disk fills while I'm using sugar" case.  

The unionfs solution is not required for the almost-full case.  We
simply need to encourage users to select files to delete before they
each all-full.  We can establish a threshold for this.

Is it impossible to remount / as a unionfs when the flash is filled past
a certain threshold?  This could be executed using the space-checking
cronjob, and proper alerts could be issued.

Erik