On 05/06/17 12:06, CoolCold wrote:
Hello! Keep testing the new box and while having not the best sync speed, it's not the worst thing I found. Doing FIO testing, for RAID10 over 20 10k RPM drives, I have very bad performance, like _45_ iops only.
<snip>
Any advises would be very helpful.
The best advice I can give you is to take a step back, and try to be clear what problem you are trying to solve here. What is this system supposed to do? What are your requirements? What are your use-cases?
Attempting to optimise the sync speed (or IOPS) of a 20 drive RAID10 set is a totally pointless exercise in itself. At best, it would be a torture test for md raid. There is no system in the world where the specifications are "make the fastest 20 drive RAID10 setup" - at least, not from a sane IT management.
When you have a clear picture of what you actually /need/, what you /want/, what you /have/, and how you want to use it all - /then/, and only then, is it time to look at possible RAID setups, filesystem arrangements, alternative hardware, etc. Then you ask for advice on this list (or elsewhere - but this list is a good starting point), learning about the pros and cons of a variety of possible arrangements.
Once you have collected these ideas, with different balances in performance, safety, space efficiency, features, cost, etc., you can then test them out and look at benchmarks to see if they will work in practice.
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