4 ms·
>storage [...] bit flipping As someone with no storage expertise I'm curious, does anyone know the likelyhood of an error resulting in a bit flip rather than a
by Dibby053 3y ago
>storage [...] bit flipping
As someone with no storage expertise I'm curious, does anyone know the likelyhood of an error resulting in a bit flip rather than an unreadable sector? Memory bit flips during I/O are another thing but I'd expect a modern HDD/SSD to return an error if it isn't sure about what it's reading.
- halfcat 3y agoNot sure if this is what you mean, but most HDD vendors publish reliability data like “Non-recoverable read errors per bits read”: https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/internal-drives/wd-red-hdd/product-brief-western-digital-wd-red-hdd.pdf https://documents.westerndigital.com/content/dam/doc-library...
- Dibby053 3y agoThanks for the link. I think that 10^14 figure is the likelyhood of the disk error correction failing to produce a valid result from the underlying media, returning a read error and adding the block to pending bad sectors. A typical read error that is caught by the OS and prompts the user to replace drives. What I understand by bit flip is a corruption that gets past that check (ie the "flips balance themselves" and produce a valid ECC) and returns bad data to the OS without producing any errors. Only a few filesystems that make their own checksums (like ZFS) would catch this failure mode. It's one reason I still use ZFS despite the downsides, so I wonder if I'm being too cautious about something that essentially can't happen.