On 05/06/17 14:30, CoolCold wrote:
Hello!
Thanks for your proposals.
From my POV, having ~ 100 iops per drive is completely okay, as you
see from iostat/fio output it's not even near the case.
Hope this clarifies.
No, that tells me absolutely /nothing/.
Please re-read what I wrote, and think about it. When you can tell us
what you plan to /do/ with your disk array, it will be possible for
people to give you /real/ help and useful advice. As it is, the best
you can get is suggestions for the colour of your bike shed.
mvh.,
David
On Mon, Jun 5, 2017 at 5:55 PM, David Brown <david.brown@xxxxxxxxxxxx> wrote:
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.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
