While large objects are not stored contiguously, the chunk size is configurable (as Alan pointed out). Increasing the chunk size increases memory usage and decreases the number of seeks required to read an object. It does not decease the number of seeks required to write the object because we use a write buffer which is separately sized for write aggregation.
The default chunk size is set such that for spinning media (HDDs) the amount of time spent reading the object is dominated by transfer time, meaning that total disk time will decrease by only a small amount if the chunk size is increased. Indeed for SSDs, the chunk size can be decreased to free up more memory for the RAM cache and to decrease the number of different block sizes. On Thu, Jun 1, 2017 at 5:46 AM, Alan Carroll < solidwallofc...@yahoo-inc.com.invalid> wrote: > You might try playing with the expected fragment size. That's tunable and > you can get a partial effect of more contiguous fragments by making it > larger, although I think the absolute maximum is 16M. This doesn't cost > additional disk space as it is a maximum fragment size, not a forced one. > >
