Re: IO scheduler recommendation

AB_ba# wrote:
> I searched the complete PostgreSQL Documentation but didn't get anything with respect to IO scheduler recommendation.
> What is being recommended by PostgreSQL ?

There is no clear recommendation.

I personally have seen workloads where changing from "cfq" to "deadline"
or "noop" improved performance by a factor of 4, but on many systems "cfq"
seems to be doing at least as good as the others.

I believe that it depends a lot on your hardware configuration and
your workload, and you are best advised to run a realistic load test.

> Which is the best IO scheduler considering the Data is hosted on NFS?

No idea - probably depends on what is behind the NFS.

Make sure to use hard, fg mounts.
If you can, use "jumbo frames" so that an 8KB block can fit into
a single IP frame.

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com