NAND Full Requirement

Deepak Saxena dsaxena at
Tue Jul 22 15:27:46 EDT 2008

On Jul 22 2008, at 16:16, Erik Garrison was caught saying:
> See:
> On boot, check NAND discomfort level.  If high, use unionfs(4) to mount
> a read/write tmpfs over top of a read-only jffs2 rootfs.  Set unionfs
> flags to enable file deletion from the 'ro' root partition (or if this
> is impossible, mount the fs in another location to allow deletions).
> Set a flag to tell olpc-session or Sugar to enter into a deletion
> dialog.  

I'm wondering if we should/can implement the file deletion UI as a small
standalone app that can be launched from the intramfs itself? This
would allow us to solve the the issues on deployed systems by just 
updating the olpcrd file?

> Benefits:
> This solution theoretically allows all software to run an a NAND-full
> machine.  Thus students who arrive at school with a NAND-full machine
> could still work with their XO through lessons and manage flash cleanup
> as time is available.  Requires minimal code-level changes to enable.

One issue here is that if the user launches an activity and changes to
documents go to the tmpfs, they are lost at boot up unless there is 
an explicit sync to the real filesystem; however, that sync can't happen
until space has been cleared.


Deepak Saxena <dsaxena at>

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