4 ms·

The scrub is done by your software, like ceph etc.

• wtallis 6y ago
  I'm not quite sure what you mean there. Your software certainly should do regular scrubs, but there are a lot of storage systems out there that don't do this. And there most definitely are SSDs that do their own scrub akin to what host software can do.
• notacoward 6y ago
  Yes. The combination of erasure coding plus regular scrubbing is already the standard in the largest proprietary storage systems. As it happens, I worked on exactly the scrubbing piece ("anti entropy") for such a system at Facebook. There was a lot of analysis of data-loss probabilities based on encodings, placement across power/network domains, scrub rates, repair rates, etc. Since there are also performance and resource-use implications behind many of these, it's actually a very complex balancing act. That's why the knowledge of these second- or third-order problems and their solutions is slowly filtering down to storage systems you can deploy yourself.