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Unpowered SSDs slowly lose data

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Re: Unpowered SSDs slowly lose data

#31

Post by PunchyHamster »

dpoloncsak wrote: post #4
paulkrush wrote: post #2

I had to search around and feel like a dork not knowing this. I have my data backed up, but I keep the SSDs because it's nice to have the OS running like it was... I guess I need to be cloning the drives to ISOs and storing on spinning rust.

I could be wrong, but I believe the general consensus is along the lines of "SSDs for in-use data, it's quicker and wants to be powered on often. HDDs for long-term storage, as they don't degrade when not in use nearly as fast as SSDs do.

I'd imagine HDDs also don't like not spinning for years(as mechanical elements generally like to be used from time to time). But at least platters itself are intact

Re: Unpowered SSDs slowly lose data

#32

Post by PunchyHamster »

loloquwowndueo wrote: post #19
bossyTeacher wrote: post #9

This is why I would rather pay someone a couple of dollars per year to handle all this for me. If need be pay two providers to have a backup.

Who do you pay for this? (To rephrase : which cloud storage vendors do you use?) interested in the $2/month price point :)

Backblaze B2 is $6TB/mo, so if you have around 300GB... stuff like restic or kopia backups nicely to it

Re: Unpowered SSDs slowly lose data

#33

Post by Terr_ »

loloquwowndueo wrote: post #19
bossyTeacher wrote: post #9

This is why I would rather pay someone a couple of dollars per year to handle all this for me. If need be pay two providers to have a backup.

Who do you pay for this? (To rephrase : which cloud storage vendors do you use?) interested in the $2/month price point :)

I assume "couple of" was figurative, to indicate the cost is substantially less than managing your own bank of SSDs and ensuring it is periodically powered etc.

[Edit: LOL, I see someone else posted literally the same example within the same minute. Funny coincidences.]

That said, they could also be storing relatively small amounts. For example, I back up to Backblaze B2, advertised at $6/TB/month, so ~300 MB at rest will be a "couple" bucks.

Re: Unpowered SSDs slowly lose data

#34

Post by 867-5309 »

ggm wrote: post #22
loloquwowndueo wrote: post #19

Earlier quoted context omitted.

Who do you pay for this? (To rephrase : which cloud storage vendors do you use?) interested in the $2/month price point :)

tell me about this $2/week filestore option. I'm interested.

continuing the bizarre trend, I'm here for the $2/day deal

Re: Unpowered SSDs slowly lose data

#35

Post by tcfhgj »

traceroute66 wrote: post #15

I assume this blog is a re-hash of the JDEC retention standards[1]. The more interesting thing to note from those standards is that the required retention period differs between "Client" and "Enterprise" category. Enterprise category only has power-off retention requirement of 3 months. Client category has power-off retention requirement of 1 year. Of course there are two sides to every story... Enterprise category s…

With 1 year power-off retention you still loose data, so still a compromise on data retention

Re: Unpowered SSDs slowly lose data

#36

Post by PaulKeeble »

testartr wrote: post #25

what is the exact protocol to "recharge" an ssd which was offline for months? do I just plug it in and let the computer on for a few minutes? does it needs to stay on for hours? do I need to run a special command or TRIM it?

We really don't know. One thing I wish some of these sites would do is actually test how long it takes for the drives to decay and also do a retest after they have been left powered for say 10 minutes to an hour, read completely, written to a bit etc and see if they can determine what a likely requirement is.

The problem is the test will take years, be out of date by the time its released and new controllers will be out with potentially different needs/algorithms.

Re: Unpowered SSDs slowly lose data

#37

Post by Terr_ »

PunchyHamster wrote: post #32
loloquwowndueo wrote: post #19

Earlier quoted context omitted.

Who do you pay for this? (To rephrase : which cloud storage vendors do you use?) interested in the $2/month price point :)

Backblaze B2 is $6TB/mo, so if you have around 300GB... stuff like restic or kopia backups nicely to it

Recently started fiddling with restic and B2, it worked fairly seamlessly once I stopped trying too hard being fancy with permissions and capabilities (cap_dac_read_search). There were some conflicts trying to have both "the way that works interactively" [0] versus "the way that works well with systemd". [AmbientCapabilities=]

One concern I have is B2's downloading costs means verifying remote snapshots could get expensive. I suppose I could use `restic check --read-data-subset X` to do a random spot-check of smaller portions of the data, but I'm not sure how valuable that would be.

I like how it resembles LUKS encryption, where I can have one key for the automated backup process, and a separate memorize-only passphrase for if things go Very Very Wrong.

[0] https://restic.readthedocs.io/en/latest/080_examples.html#ba...

Re: Unpowered SSDs slowly lose data

#38

Post by fragmede »

ggm wrote: post #21
gosub100 wrote: post #13

Earlier quoted context omitted.

or you could power them on 1-2x /year.

Power them on and run something to exercise the read function over every bit. Thats why a ZFS filesystem integrity check/scrub is the useful model. I'm unsure if dd if=/the/disk of=/dev/null does the read function.

why would it not? it's a low level tool to do exactly that. you could "of" it to somewhere else if you're worried it's not. I like to | hexdump -C, on an xterm set to a green font on a black background for a real matrix movie kind of feel.

Re: Unpowered SSDs slowly lose data

#40

Post by ethin »

brian-armstrong wrote: post #20
derkades wrote: post #16

Earlier quoted context omitted.

Isn't that the SSD controller's job?

It would surely depend on the SSD and the firmware it's running. I don't think you can entirely count on it. Even if it were working perfectly, and your strategy was to power the SSD on periodicially to refresh the cells, how would you know when it had finished?

NVMe has read recovery levels (RRLs) and two different self-test modes (short and long) but what both of those modes do is entirely up to the manufacturer. So I'd think the only way to actually do this is to have host software do it, no? Or would even that not be enough? I mean, in theory the firmware could return anything to the host but... That feels too much like a conspiracy to me?
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