[Samba] Troubleshooting poor (small) random read performance -- serverid.tdb?
jra at samba.org
Thu Jun 19 15:37:30 MDT 2014
On Thu, Jun 19, 2014 at 11:52:12AM -0700, Ray Van Dolson wrote:
> Shoot, wish I'd done some Googling and stumbled across that prior to
> bumping up to RHEL7!
> With that said, here are a couple of updates:
> All configs are using "default" options plus these:
> aio read size = 1
> aio write size = 1
> strict locking = no
> use sendfile = yes
> - RHEL 7.0 with the stock Samba 4.1.1 - no significant improvement
> observed on the application side. smbd processes still showed very
> high CPU utilization, system load went up to 10 but minimal disk
> activity seen. strace on smbd processes looked significantly
> different from what I saw on 3.6.x. My fu wasn't strong enough to
> discern where most time was being spent.
> - RHEL 7.0 with Sama 4.1.8 stolen from Fedora 20 - definite improvement
> observed. System load stayed around 1.0 or lower and on the
> application side we saw processing occurring at a pretty good clip,
> though not as good as Windows. There are parent processing nodes and
> children processing nodes... some of the child nodes didn't get fully
> "spun up" and were complaining about being unable to access some of
> the data they needed.... which led us to....
> - RHEL 7.0 with Samba 4.1.8 and "locking = no" set on the share from
> which data is being read. Best results by far -- basically matched
> Windows performance. All parent and "child" nodes had their CPU's
> fully maxed out indicating they were able to get at the data they
> needed quickly.
So are you using "locking = no", "strict locking = no"
or "posix locking = no" ?
That's not entirely clear from your message, and would
be an interesting data point to know !
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