On Jan 14, 2008 3:15 PM, Monty J. Harder <mjharder(a)gmail.com> wrote:
>
>
> On Jan 14, 2008 11:09 AM, Oren Beck <orenbeck(a)gmail.com> wrote:
>
> > Accumulate write counts to a buffer in session ram- and write to flash
> > only as part of unmount, or shutdown where unmount was not explicit but
> > presumed.
>
>
> That shouldn't be necessary. Internally, flash drives save information
> along with each data block that isn't presented via the USBMSD interface.
> When I write Sector X of a filesystem to the flash drive, it doesn't always
> write the same physical location. Instead, it writes the new version of
> that sector to another location, and has some way of knowing which version
> is current. I don't know the internals, but it's probably using some kind
> of serial number that increments with each write.
>
> At least that's how I would implement something like that. The device
> should be able to non-destructively determine how many sector writes it has
> performed, and how many sectors are nearing the expected lifetime.
>
>
That was part of my original concept- that such data was "present" merely
needing to be accessed and externally
readable.
The open queries are 2.
1. IS a device with 80% of it's estimated "life" used still "Stable" for
archive use? Defined as whatever data is the "Last Writes" remaining stable
for the same # of years as a written to "less" device or not. With
qualifiers on confidence levels and non-obvious issues.
2. Agreement on flag or bit to declare a flash device "Archive" .
--
Oren Beck
816.729.3645