On 18 January 2016 at 03:20, Dallas Clement <dallas.a.clement@xxxxxxxxx> wrote: > > Thanks. I have been playing around with this fsync parameter. I have > tried various numbers ranging from 32 to 128. I do see reasonable > numbers now. However throughput is quite a bit less than I was seeing > with direct I/O (direct=1). I was expecting I would actually get > better performance with buffered I/O. Am I misguided? I would expect async direct I/O to be able to go faster (speed is it's mostly what it's there for...). Direct asynchronous I/O can be faster because you don't have the overhead of copying things into the page cache. Additionally, you don't necessarily suffer from head of line blocking - each I/O can potentially finish independently of any other. -- Sitsofe | http://sucs.org/~sits/ -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
