Conversation
WiteWulf@cyberplace.social

Gary Parker party_porg

Oh, this is interesting (and a little scary)

tl;dr don’t use SSDs for long term, offline storage. The data degrades after as little as two years without the drives being powered up

https://www.tomshardware.com/pc-components/storage/unpowered-ssd-endurance-investigation-finds-severe-data-loss-and-performance-issues-reminds-us-of-the-importance-of-refreshing-backups

1
19
2
pavel

Pavel Machek

Reply to @WiteWulf@cyberplace.social
@WiteWulf Flash needs periodic scrubbing, that should be well known? And yes, scrubbing is hard to do with power off :-). Retention on flash also depends on temperature when data was stored and storage temperature, if you want more fun :-).
1
1
7
WiteWulf@cyberplace.social

Gary Parker party_porg

Reply to @pavel

@pavel it is not well known to the vast majority of users.

1
0
0
pavel

Pavel Machek

Reply to @WiteWulf@cyberplace.social
@WiteWulf Well, if you want more scary stuff... cut SSD power during write operation. It is quite hard to get FTL right, and I'm pretty sure some vendors simply don't. Result is... a brick.
1
1
3
dalias@hachyderm.io

Cassandrich

Reply to @pavel

@pavel @WiteWulf I suspect this is the cause of most rpi sd card corruption, and it's the result of host computer cheaping out on basically one capacitor that could ensure card retains power for a minimum period of time after host has gone down and new commands are no longer possible.

1
0
1
pavel

Pavel Machek

Reply to @dalias@hachyderm.io
@dalias @WiteWulf Yes, that's likely a problem. And my guess is that a) it is not clear how big capacitor is required and b) rpi expects well-designed cards and cards expects power-supply that does not cut out randomly :-(.
1
0
1
dalias@hachyderm.io

Cassandrich

Reply to @pavel

@pavel @WiteWulf The needed size should be easily computable from the max current SD card is allowed to pull and the max write time in the spec or something like that.

1
0
1
pavel

Pavel Machek

Reply to @dalias@hachyderm.io
@dalias @WiteWulf Its not that simple. SSDs are not that deterministic, and they may need to perform writes even when host does not request writes, due to garbage collection or scrubbing.
0
0
0
About social.kernel.org

Terms of service

  1. Please do not use this service in violation of the Linux Kernel Code of Conduct. Doing so will result in your account suspension with the referral of the matter to the CoC committee.

  2. "Repeating"/"boosting" someone else's status on this platform will be treated as endorsement and will fall under rule #1.

  3. You are encouraged to use this platform to promote your work on the Linux Kernel, but there is no restriction on permitted topics (with the exception of anything covered by #1 above).

  4. There is no requirement to post in English, but it should be considered the primary language of communication on this platform.

Privacy notice

The admins of this service have access to all posted statuses. They aren't looking, but if it's something they shouldn't know about, then you should not post it on this platform.

Please see the Linux Foundation Privacy Policy, which applies to this platform as well.

Getting your own account

If you would like an account on this instance, please check that the following applies to you:

  • You are listed in MAINTAINERS or CREDITS

  • OR: You have a kernel.org account or email address

  • OR: You have a long and established history of involvement with the Linux Kernel

If the above is true and you agree with the Terms of Service and Privacy Notice listed above, please use these instructions to request an account: