On Jan 14, 2008 3:15 PM, Monty J. Harder [email protected] wrote:
On Jan 14, 2008 11:09 AM, Oren Beck [email protected] 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" .