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I wonder how much of this could have been solved by using a different file system. There is all of this talk about the physical layer but no mention of the fil
by snarfy 10y ago
I wonder how much of this could have been solved by using a different file system. There is all of this talk about the physical layer but no mention of the file system used.
> Typically, write amplification refers to a problem with writing data to SSD disks: a small logical update (say, writing a few bytes) becomes a much larger, costlier update when translated to the physical layer.
This is exactly the type of problem solved by the file system layer.
- pritambaral 10y agoHow would any filesystem help with that? SSDs typically write entire blocks, even if the OS asks them to only write a few bytes. That's just how SSDs work.
- Terretta 10y agoRethink the file system. Think log-structured.
- pritambaral 10y agoDoesn't matter. Even a log-structured fs, when told to write 4 bytes of new data to disk will have to write those 4 bytes immediately and return. If an application asks the OS (via fsync), and the OS asks the fs and the fs doesn't write to disk but tells the OS it did, then the fs just lied and risked data loss. If power is lost between the fs lying to the OS and its subsequently actually writing to disk, the data that the fs lied about is lost. You don't want that with a DB on top of it.