4 ms·
I wonder if a single bad bit could permanently destroy a whole ~16MiB sector? So SMR drives would need significantly more reserves to compensate for that.
by PixelOfDeath 5y ago
I wonder if a single bad bit could permanently destroy a whole ~16MiB sector? So SMR drives would need significantly more reserves to compensate for that.
- petertodd 5y agoShingled drives can still be read sector-by-sector. The shingling just changes how the data is written; it doesn't change how the data is read. So no, a single bad bit would only affect a single sector. And in fact, a single bad bit wouldn't do any harm, as all drives use error correcting codes that can handle a lot more than a single bit going bad. You'd actually lose a whole sector at time (512 bytes or 4096 bytes, depending on the drive).
- magicalhippo 5y agoThe difference between a regular and a SMR drive is that the SMR drives have a narrower read head compared to the write head. This means that when writing data it overwrites neighboring tracks, and hence writing is partially overlapped like shingles. Apart from that they're more or less the same as normal drives as far as I know, firmware aside. So a single bad bit shouldn't affect more than in a non-SMR drive.
- magicalhippo 5y agoAm I mistaken? If so I would appreciate a correction. I based my post primarily on what I recalled from this talk[1] by a HGST engineer. [1]: https://youtu.be/a2lnMxMUxyc?t=556 https://youtu.be/a2lnMxMUxyc?t=556