2 ms·
As the article tries to state, the problem isn't that bad blocks can happen. The problems with md's bad blocks log are: - Most of the time the entries don't co
by grifferz 6y ago
As the article tries to state, the problem isn't that bad blocks can happen. The problems with md's bad blocks log are:
- Most of the time the entries don't correspond to actual bad blocks.
- It's buggy because it copies BBL between devices leading to another instance of "says the blocks are bad but they actually aren't"
- Once you've worked out that the entries are bogus it is still very hard to remove the entries or the BBL as a whole
- It's overly quiet in what it does. I monitor my syslogs but many people don't. There are many documented instances of people carrying entries in a BBL for years without knowing.
- Once MD thinks there is a bad block it renders that block on that device useless for recovery purposes. So in a two device array you just lost redundancy.
So this article has very little to do with the concept of bad blocks; it's about how md's BBL feature can be dangerous and why I don't want it enabled until it's fixed.