New top story on Hacker News: Ask HN: What are some good resources for learning about low level disk/file IO?

Ask HN: What are some good resources for learning about low level disk/file IO?
10 by nlnn | 2 comments on Hacker News.
I've been messing around with writing a toy database for fun/learning, and realised I've got a fairly big gap in my knowledge when it comes to dealing with performance and durability when dealing with file reads/writes. Example of some questions I'd like to be able to answer or at least make reasonable decisions about ( note : I don't actually want any answers to the above now, they're just examples of the sort of thing I'd like to read in depth about, and build up some background knowledge): * how to ensure data's been safely written (e.g. when to flush, fsync, what guarantees that gives, using WAL) * blocks sizes to read/write for different purposes, tradeoffs, etc. * considerations for writing to different media/filesystems (e.g. disk, ssd, NFS) * when to rely on OS disk cache vs. using own cache * when to use/not use mmap * performance considerations (e.g. multiple small files vs. few larger ones, concurrent readers/writers, locking, etc.) * OS specific considerations I recall reading some posts (related to Redis/SQLite/Postgres) related to this, which made me realise that it's a fairly complex topic, but not one I've found a good entry point for. Any pointers to books, documentation, etc. on the above would be much appreciated.