How does the readahead mechanism works？

[201341]

I want to know how juicefs uses the memory cache to speed up reading and writing. The docs say the buffer-size control the write buffer cache and readAhead buffer cache. Does it mean the buffer size is the sum of write cache and readAhead cache or the read cache and write cache have this much capacity respectively？

Can the readAhead cache can accelerate random read? And can i disable the readAhead cache if i just want to use the cache to speed up the write?

[Jack47]

+1

[xiaogaozi]

You may refer to this document: https://juicefs.com/docs/community/guide/cache#readahead-prefetch