TIL that SSDs can lose data if left unplugged for long periods of time (only required to hold data up to 1 year), unlike HDDs which as long as the material holds it can take years.

@djlink IMO the only material proven to hold digital data for decades at this point is tape, as evidenced by the tape reels they keep finding in storage warehouses whose contents are successfully read back https://www.tomshardware.com/software/linux/recovered-unix-v4-tape-quickly-yields-a-usable-operating-system-nostalgia-addicts-can-now-boot-up-unix-v4-in-a-browser-window

I suppose HDDs can hold archival data, but there are way more ways for spinning discs to fail than tape when stored for long periods of time. But maybe we can use magnetic microscopy to recover their data even if their circuits have died, their motors have failed, or their lubricants have died out. https://garnerproducts.com/hubfs/ucsd_recovery_of_partially_degaussed-hdds.pdf

@funkylab @raymaccarthy @djlink Reports of tape or conventional hard drives lasting decades are largely survivorship bias. Nobody talks about the tapes which decayed from poor storage or the disks with phenolic boards which crumble when you look at them. They *are likely* to retain usable data for longer than SSDs *are likely* to retain usable data, but there’s huge overlap between those curves.

The only real way to store data long-term and ensure it remains readable is to test it periodically (e.g, a ZFS scrub). Media failures are inevitable. The best approach is designing for this and testing to catch the faults before they overcome the fault tolerance of the system.

TIL that SSDs can lose data if left unplugged for long periods of time (only required to hold data up to 1 year), unlike HDDs which as long as the material holds it can take years.

Edit: added link: https://www.slashgear.com/1893447/dont-leave-your-old-ssd-unplugged/

@djlink I've kept one of my external SSDs on top of my computer for like a year, so I haven't been cooking my files so much as I have been flame-grilling them.

TIL that SSDs can lose data if left unplugged for long periods of time (only required to hold data up to 1 year), unlike HDDs which as long as the material holds it can take years.

Edit: added link: https://www.slashgear.com/1893447/dont-leave-your-old-ssd-unplugged/

TIL that SSDs can lose data if left unplugged for long periods of time (only required to hold data up to 1 year), unlike HDDs which as long as the material holds it can take years.

Edit: added link: https://www.slashgear.com/1893447/dont-leave-your-old-ssd-unplugged/

@raymaccarthy @djlink I'm really not sure where the idea that a powered SSD would be more reliable than an unpowered one – that could only be true if it would be re-writing itself in the background, which would, counter to the intent, make it wear out faster, unless the SSD is essentially unused and the re-writing was free to use arbitrary much rarely or never used pages to copy the data to. But even that would be very undesirable – who wants an SSD with a standby power usage as if written to?)

@funkylab @djlink
Not powered off they don't.
An HDD can wear out with use but 25 years is easy for storage in a drawer or box in the attic. Floppy storage is far trickier.
Tape needs carefully stored.
Pressed DVDs* and especially pressed CDs are OK, but "written" ones can fade in daylight.

[* Assuming no manufacturing defects]

@raymaccarthy @funkylab @djlink Hard disks also wear out if stored. However your wear is mostly component failures, oxidisation and so on so quite slow. The flash chips on the hard disk drive today will also eventually dribble their brains out and it won't work any more but the flash used is generally rather less vulnerable than the very high density flash used in an SSD.

Unlike the SSD though your HDD media is more recoverable even if the electronics is dead.

@funkylab @raymaccarthy @djlink Modern SSDs do patrol scrubbing so they do indeed rewrite bad information or marginal data when needed.
Spinny rust has btw done the same thing for many years too, some spinny rust is even smart enough to relocate data behind your back so you don't even find out about the bit of the disk that's getting dodgy for some reason.

@raymaccarthy @djlink I'm really not sure where the idea that a powered SSD would be more reliable than an unpowered one – that could only be true if it would be re-writing itself in the background, which would, counter to the intent, make it wear out faster, unless the SSD is essentially unused and the re-writing was free to use arbitrary much rarely or never used pages to copy the data to. But even that would be very undesirable – who wants an SSD with a standby power usage as if written to?)