On Sun, Feb 22, 2015 at 6:30 AM, Roman Mamedov [off-list ref] wrote:

On Sun, 22 Feb 2015 12:31:23 +0100
Christer Solskogen [off-list ref] wrote:

quoted

There are so many different views on the internet

...and yet you're asking for some more? :)

quoted

Is there even such a thing as optimal chunk size?

64K should be fine:
http://louwrentius.com/linux-raid-level-and-chunk-size-the-benchmarks.html

I have seen that people report 64K chunk size results better
performance. However, I was not able to find why mdadm maintainers
decided to switch into 512K default chunk size a few years ago ? Was
that decision related to the write-intent bitmap overhead ?