Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

SSDs lose data if left without power for just 7 days

ibtimes.co.uk

Post reply on HN
Print view View original

11–20 of 29 posts

Re: SSDs lose data if left without power for just 7 days

#11

Post by dne »

Someone missed an important part of the standard (JEDEC JESD218, section 6.3): "This standard is based on a use scenario in which the SSDs are actively used for some period of time during which the SSDs are written to their endurance ratings, followed by a power-down time period in which data must be retained."

E.g. in Intel's product spec for the DC S3500 series, the data retention parameter is specified as: "3 months power-off retention once SSD reaches rated write endurance at 40 °C".

Re: SSDs lose data if left without power for just 7 days

#12

Post by dogma1138 »

lectrick wrote: post #3

I assume 7 days is worst-case scenario, corporate-level drive quality (which is lower than consumer-grade) plus high temperature? Is it becoming necessary to switch to a filesystem that ensures data integrity with redundancy and regular checksums?

most corporate level SSD's are actually better than entry level consumer ones.

Re: SSDs lose data if left without power for just 7 days

#13

Post by lectrick »

dogma1138 wrote: post #12
lectrick wrote: post #3

I assume 7 days is worst-case scenario, corporate-level drive quality (which is lower than consumer-grade) plus high temperature? Is it becoming necessary to switch to a filesystem that ensures data integrity with redundancy and regular checksums?

most corporate level SSD's are actually better than entry level consumer ones.

Not according to the article :O

I presume it is assumed that corporate policy has better data integrity best practices than your average Joe Homeowner.

Re: SSDs lose data if left without power for just 7 days

#14

Post by creshal »

JohnBooty wrote: post #4

According to a recent presentation by Seagate's Alvin Cox, who is also chairman of the Joint Electron Device Engineering Council (JEDEC), the period of time that data will be retained on an SSD is halved for every 5 degrees Celsius (9 degrees Fahrenheit) rise in temperature in the area where the SSD is stored. "SSDs scary," says leading manufacturer of mechanical hard drives. "Mechanical drives good! SSDs baaaaaad! Y…

Seagate is also a manufacturer of SSDs…

Re: SSDs lose data if left without power for just 7 days

#15

Post by thrownaway2424 »

JohnBooty wrote: post #4

According to a recent presentation by Seagate's Alvin Cox, who is also chairman of the Joint Electron Device Engineering Council (JEDEC), the period of time that data will be retained on an SSD is halved for every 5 degrees Celsius (9 degrees Fahrenheit) rise in temperature in the area where the SSD is stored. "SSDs scary," says leading manufacturer of mechanical hard drives. "Mechanical drives good! SSDs baaaaaad! Y…

JEDEC is not some oxide-industry puppet group. It's a major standards body.

Re: SSDs lose data if left without power for just 7 days

#17

Post by dogma1138 »

What a bunch of nonsense... Here is the presentation: http://www.jedec.org/sites/default/files/Alvin_Cox%20%5BComp...

All what they found is that there's a correlation between load, the operation temperature during which data was stored, and the ambient temperature in which the device is kept while switched off. This means that at an active operational temperature of about 40c (which is normal for most consumer drives) and a storage temperature of 30c (which is pretty much the upper maximum of storage temperatures under residential conditions) your drive will retain data for at least 52 weeks.

Re: SSDs lose data if left without power for just 7 days

#18

Post by baruch »

The paper took something out of context, didn't really understand what it reads and published nonsense.

The original blog post linked from the article is https://blog.korelogic.com/blog/2015/03/24#ssds-evidence-sto...

It actually raises a point for a specific use-case, when a computer with an SSD is taken for analysis (f.ex. a court case as evidence by the police) the SSD is kept powered off and may lose its data and thus be worthless as evidence after some time if the system is not kept in a normal temperature (around 25C).

It's not a normal use-case and in fact it may be to the benefit of the user to use an SSD in that case in the hope that the data will self-destruct with complete plausible deniability.

Re: SSDs lose data if left without power for just 7 days

#19

Post by baruch »

lectrick wrote: post #13
dogma1138 wrote: post #12

Earlier quoted context omitted.

most corporate level SSD's are actually better than entry level consumer ones.

Not according to the article :O I presume it is assumed that corporate policy has better data integrity best practices than your average Joe Homeowner.

The requirements for an enterprise SSD is lower than that of the consumer SSD under the assumption that such SSDs are hardly ever left unpowered for an extended period of time.

The SSD is in fact better because it better uses its internal resources to optimize for things other than retention without power.

Re: SSDs lose data if left without power for just 7 days

#20

Post by creshal »

lectrick wrote: post #13
dogma1138 wrote: post #12

Earlier quoted context omitted.

most corporate level SSD's are actually better than entry level consumer ones.

Not according to the article :O I presume it is assumed that corporate policy has better data integrity best practices than your average Joe Homeowner.

According to the slides, Enterprise SSDs are tested to much stricter standards (one order of magnitude better error rate).
Post reply on HN