[Linux-cluster] |Optimizing DLM Speed

[Steven Whitehouse]

Hi,

On Wed, 2011-05-18 at 18:34 +0100, Alan Brown wrote:
> Steven Whitehouse wrote:
> > Hi,
> > 
> > On Wed, 2011-05-18 at 16:14 +0100, Alan Brown wrote:
> >> Bob, Steve, Dave,
> >>
> >> Is there any progress on tuning the size of the tables (RHEL5) to allow 
> >> larger values and see if they help things as far as caching goes?
> >>
> > There is a bz open, 
> 
> I thought so, but I can't find it.
> 
Its #678102, which you are on the cc list of. It probably needs a RHEL5
bug as well. Bryn posted a patch to it to make the change, but I'm not
sure of the current status. I'm copying in Dave Teigland so that he can
comment on the current status.

> > and you should ask for that to be linked to one of
> > your support cases, if it hasn't already been. I thought we'd concluded
> > though that this didn't actually affect your particular workload.
> 
> Increasing them to 4096 hasn't but larger numbers might.
> 
> >> It would be advantageous to tweak the dentry limits too - the kernel 
> >> limits this to 10% and attempts to increase are throttled back.
> >>
> > Yes, I've not forgotten this. I've been working on some similar issues
> > recently and I'll explore this more fully once I'm done with the
> > writeback side of things.
> 
> Do you have a BZ for this one?
> 
The writeback issues are under #676626 at the moment, although this is a
slightly different issue to what that bug was originally opened for.
There isn't a bug for the dentries issue as that needs to have a ticket
opened first, and then a bz opened by support if appropriate. I've
copied in Bryn so that he can pick this up and make sure that it is
done,

Steve.