4 ms·

Mechanical failure [0]. As perbu found out, when moving parts are left to sit for years, things can fail. Lube can dry up, causing bearings to seize up, actuato

Mechanical failure [0]. As perbu found out, when moving parts are left to sit for years, things can fail. Lube can dry up, causing bearings to seize up, actuators to lose precision or get completely stuck [1], and the magnetic field degrades by 1% per year [2]. Of course, you could get lucky w/r/t mechanical issues, as many retro computer enthusiasts can attest, but it seems to involve a lot of luck, as it only takes tiny defects to cause problems over a long enough time-frame that leave half your drives as paperweights while the others keep on chugging. Both of these issues can be largely mitigated by simply plugging the HDDs in every year or so and re-writing the data (maybe run badblocks while you're at it to ensure the drive is still in good health), but, as throw0101a mentioned, this takes time and effort. [0]: https://serverfault.com/a/51893 https://serverfault.com/a/51893 [1]: https://www.partitionwizard.com/clone-disk/do-hard-drives-go-bad-if-not-used.html https://www.partitionwizard.com/clone-disk/do-hard-drives-go... [2]: https://superuser.com/a/312764 https://superuser.com/a/312764

3-cheese-sundae 3y ago
Is there a way to force a file system to recommit its data?
- jandrese 3y ago
  Seems like you could do it by not even mounting the filesystem, just read out raw sectors and write them back. Like a 3 line program. Maybe if you want to be fancy you compare the sectors to some checksums to make sure you're not reading corrupt data.
e12e 3y ago
Any word on SSDs?
- saltminer 3y ago
  SSDs may actually worse than HDDs, depending on what NAND chips are in use. Although there are no moving parts to seize up, they do require an occasional power up because they represent data via voltage levels and we have not yet found a perfect insulator (meaning they will inevitably leak charge), and with QLC being all the rage these days (4 bits represented in each cell using one of 16 discrete voltage levels), when the voltage levels start to degrade, it could easily cause catastrophic bit rot. How long a given SSD will last before losing data depends on the chips it is built with. I remember reading that Sandisk rates their flash storage as being able to survive a year without power (though I read that years ago and cannot find a source for it now), though [0] says 2-5 years, so technology has likely advanced since I last read about this. Either way, you should probably try and power up your SSDs at least once a year to keep the cells charged. This is less work than to keep an HDD healthy for cold storage, but it certainly isn't "set and forget" like tapes or optical disks. Edit: I remember pulling my first SSD, a 60 GB Intel 330, from an old laptop and, despite having not been powered on for 3 years, it still booted. But that was MLC/DLC [1], which only has 4 voltage states, and I only saw that it booted, not that all my old data was intact. [0]: https://www.easeus.com/resource/does-ssd-need-power.html https://www.easeus.com/resource/does-ssd-need-power.html [1]: https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-330-specification.pdf https://www.intel.com/content/dam/www/public/us/en/documents...
  - e12e 3y ago
    Hm. Makes me more sad about the state of zfs in macOS and windows - with native encryption and checksums it makes for a nice cross-platform fs for external drives...

3-cheese-sundae 3y ago

Is there a way to force a file system to recommit its data?

jandrese 3y ago
Seems like you could do it by not even mounting the filesystem, just read out raw sectors and write them back. Like a 3 line program. Maybe if you want to be fancy you compare the sectors to some checksums to make sure you're not reading corrupt data.

e12e 3y ago

Any word on SSDs?

saltminer 3y ago
SSDs may actually worse than HDDs, depending on what NAND chips are in use. Although there are no moving parts to seize up, they do require an occasional power up because they represent data via voltage levels and we have not yet found a perfect insulator (meaning they will inevitably leak charge), and with QLC being all the rage these days (4 bits represented in each cell using one of 16 discrete voltage levels), when the voltage levels start to degrade, it could easily cause catastrophic bit rot. How long a given SSD will last before losing data depends on the chips it is built with. I remember reading that Sandisk rates their flash storage as being able to survive a year without power (though I read that years ago and cannot find a source for it now), though [0] says 2-5 years, so technology has likely advanced since I last read about this. Either way, you should probably try and power up your SSDs at least once a year to keep the cells charged. This is less work than to keep an HDD healthy for cold storage, but it certainly isn't "set and forget" like tapes or optical disks. Edit: I remember pulling my first SSD, a 60 GB Intel 330, from an old laptop and, despite having not been powered on for 3 years, it still booted. But that was MLC/DLC [1], which only has 4 voltage states, and I only saw that it booted, not that all my old data was intact. [0]: https://www.easeus.com/resource/does-ssd-need-power.html https://www.easeus.com/resource/does-ssd-need-power.html [1]: https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-330-specification.pdf https://www.intel.com/content/dam/www/public/us/en/documents...
- e12e 3y ago
  Hm. Makes me more sad about the state of zfs in macOS and windows - with native encryption and checksums it makes for a nice cross-platform fs for external drives...