[Gluster-users] Basic gluster questions

[Pavan]

On Tuesday 31 May 2011 11:01 PM, John Hanks wrote:
> Hi,
>
> I'm setting up gluster for the first time and have a single server
> with two bricks set up for testing:
>
> [root at filer-jdn1bp1 etc]# gluster volume info
>
> Volume Name: projects
> Type: Distribute
> Status: Started
> Number of Bricks: 2
> Transport-type: tcp
> Bricks:
> Brick1: filer-jdn1bp1:/glusterfs/0.0
> Brick2: filer-jdn1bp1:/glusterfs/0.1
> Options Reconfigured:
> nfs.disable: on
>
> Mounting this volume on the server or on a separate client over a 10
> Gbps link is working, but I'm seeing weird performance patterns. If I
> do this:
>
> time sh -c "dd if=/dev/zero of=./testfile count=32768 bs=1M; sync"
>
> in the glusterfs mounted directory on either client I see rates of
> ~250 MB/s but if I try to copy files onto the volume with either rsync
> or cpio pass-thru, the rates drop to<  10 MB/s. The directories I am
> attempting to copy are mostly large files (>  10 GB) and as I watch
> cpu, network and disk i/o stats, nothing seems to be stressed or
> blocked, it's just slow.

You cannot just look at the cpu, network, io stats and conclude that 
things are fine. You will have to look at these values in comparison 
with dthe dd case where things work according to your expectation.

When you say you are "rsync'ing to the volume", *from where* do you rsync?

Pavan

>
> I've been searching for documentation on how to possibly tune this or
> track down the bottleneck but not having much luck. Most things that
> turn up in searches seem to apply to older gluster versions and the
> 3.2 documentation is pretty sparse with respect to tuning things.
>
> Any suggestions for what I am doing wrong with this setup or any
> pointers to documentation on how to troubleshoot/tune this would be
> appreciated, especially any "intro for dummies" type docs that could
> fill in the big gaps in my understanding of how gluster works. I'm
> open to an RTFM reply, just haven't found the right manual yet myself
> and would appreciate a pointer :)
>
> Thanks,
>
> jbh
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://gluster.org/cgi-bin/mailman/listinfo/gluster-users