[Linux-cluster] GFS performance tuning

[Ross Vandegrift]

On Mon, Jun 09, 2008 at 04:16:56PM -0500, Bob Peterson wrote:
> Hi Everyone,
> 
> I just wanted to let everyone here know that I just updated the
> cluster wiki page regarding GFS performance tuning.  I added a bunch
> of information about increasing GFS performance:

Hi Bob, thanks for the additional information.  Quick questions:


> 1. How to use "fast statfs".

On a GFS2 filesystem, I see the following:
[root at sensor02 ~]# gfs2_tool gettune /rrds
...
statfs_slow = 0
...

Does that indicate that my filesystem is already using this feature?

> 2. Disabling updatedb for GFS.
> 3. More considerations about the Resource Group size and the
>    new "bitfit" function.
> 4. Designing your environment with the DLM in mind.

Do you have any specific reading material you'd suggest on this topic?
I suspect the interesting bits are related ot how GFS actually uses
the DLM to lock filesystem metadata.  I've read some of Christine's
DLM book, but there's not really anything related to GFS therein.

> 5. How to use "glock trimming".

Is the glock trimming patch present in the cluster suite from RH5?

The link provided in the Wiki went to a bugzilla bug with no info, and
URL to people.redhat.com didn't work over https.  I update that, but
wanted to make sure the Bugzilla link wasn't relevant.


-- 
Ross Vandegrift
ross at kallisti.us

"The good Christian should beware of mathematicians, and all those who
make empty prophecies. The danger already exists that the mathematicians
have made a covenant with the devil to darken the spirit and to confine
man in the bonds of Hell."
	--St. Augustine, De Genesi ad Litteram, Book II, xviii, 37