Hacker News Reader

Comment by userbinator | Hacker News Reader

According to this page, the SMART hour counter is only 16 bits, and rollover should be harmless:

http://www.stbsuite.com/support/virtual-training-center/powe...

If you look elsewhere on the Internet, you'll find people with very old and working HDDs that have rolled over, so I suspect this bug is limited to a small number of drives.

(What that page says about not being able to reset it is... not true.)

Likewise, I'm skeptical of "neither the SSD nor the data can be recovered" --- they just want you to buy a new one.

Tangentially related, I wonder how many modern cars will stop working once the odometer rolls over.

View on HN

>Likewise, I'm skeptical of "neither the SSD nor the data can be recovered"

If the firmware crashes during boot with negative hour counter, it probably could be only fixed by manually flashing new firmware over JTAG.

...and likely some of the data recovery companies already know about and are prepared for this.

$500 ~ $1k for a JTAG flash. I'm sure they have plenty of other drives that come in and they price at $1k but that take days longer than expected, so it probably all balances itself out eventually.

Or they swap boards and you eventually end up with the same problem...

In an SSD the board is the drive.

Anecdotal so you don't have to look elsewhere: I can confirm that at least two of my NAS HD drives have rolled over once. Drives usually do nothing and spin up once every two weeks or so. No problems. Though SMART only says 16 bits I also have one drive which has over 16 bit hours of operation reported and is still counting so 16 bit is not universal.

Since I run a SMART test every month it is easy to track the hourly progression (and thus rollover) in the event log as the events are reported in POH timing.

> Likewise, I'm skeptical of "neither the SSD nor the data can be recovered" --- they just want you to buy a new one.

Regarding recovery: The FTL is likely toast, in which case while the data probably is unharmed and there, it's basically a giant block-sized jigsaw puzzle. With enough effort, and all the stars align - sure, you might be able to recover some/all of it.

Regarding un-bricking/reset: Potentially, no longer any access to wear-levels at the time. So the future integrity/reliability is kind-of dubious.

I used to develop SSD firmware. Remember that these things need to handle power loss at any point in time. We store lots of redundant copies of information on the NAND so its just a matter of running the code that rebuilds everything.

Reply on news.ycombinator.com