multiple MTD partitions

[Ivan Krstić]

On Dec 17, 2007, at 1:51 AM, Joel Stanley wrote:
> JFFS2 has done an excellent job, at least on my xos, of keeping
> filesystem integrity after sudden power-offs.

Write-back caching does not adversely affect filesystem *integrity*.  
It makes a tradeoff by reducing flash write/erase frequency and  
increasing apparent filesystem performance at the cost of more  
recently-written data potentially being lost in case of power failure.

This tradeoff is eminently reasonable as a default policy. Remember  
that programs can still call fsync to force a flush to flash, and that  
more context-sensitive policy can be implemented by more context-aware  
elements of the stack. OHM could, for instance, remount the filesystem  
synchronously when battery charge goes below a threshold, or it can  
simply twiddle the /proc twaddle that twuddles the writeback timer  
twoddle.

--
Ivan Krstić <krstic at solarsail.hcs.harvard.edu> | http://radian.org