Greg Freemyer writes:
On Thu, Nov 24, 2011 at 4:47 AM, Joachim Schrod <jschrod@acm.org> wrote:
Yes, that I've read. But that was not my use case. My use case is "SSD firmware uses all sectors for wear levelling after secure erase". I don't care if the data is still on it.
Does your NDA-knowledge include information about that use case?
Please note that my posted steps include one step to unlock an SSD, so locked devices are covered.
Joachim
My NDA knowledge doesn't cover that use case. We were worried about drive sanitation (getting rid of data.)
But there are rumors of SSDs that immediately return a success upon receiving a Secure Erase command (ie. less than a second). That seems pretty hard to believe they were even doing anything with the command. ie. It takes several seconds to process a full set of trim commands even from hdparm (which is extremely efficient. See the wiper.sh script that comes with hdparm. It will invoke hdparm on a few different filesystems to trim them fully. fstrim is the new "supported" way, but it is no where near as efficient as how hdparm does it.)
Thanks a lot for your insightful information. I'll consider that. FWIW, the secure erase command (via hdparm) on my Crucial SSD needed some time to return. Btw, I have forwarded your comments concerning "leave free unpartitioned space" to some friends of mine who do storage designs for large providers for a living. AFAIK, they have access to internal information from disk manufacturers resp. storage subsystem vendors. If information is returned that I'm allowed to share, I'll forward it. Best, Joachim -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org