another Problem / question

another Problem / question

[Jens Rehpöhler]

Hi all,

todo i've done few performance tests with my two clusters.

I've used : rados -p data load-gen --run-length 10 --target-throughput 50

to generate some load. Now i have a question regarding "ceph -w" output.

The output before the test was:

2012-01-18 11:55:28.621107    pg v113011: 594 pgs: 594 peering; 61022 MB
data, 120 GB used, 244 GB / 372 GB avail

here is the output after the test:

2012-01-18 13:53:30.190602    pg v113119: 594 pgs: 594 active+clean;
1058 GB data, 120 GB used, 244 GB / 372 GB avail

How can i have more Data then the available discspace ? Is there any
possiblity to identify the rados objects of this test and delete them
manualy ?

The "xxxx GB Data" value fills up in a few seconds. So i think this
might be a display problem.

This happens on my 0.39 Cluster and also on my 0.40 cluster.

Thanks a lot

Jens

Re: another Problem / question

[Tommi Virtanen]

On Wed, Jan 18, 2012 at 05:13, Jens Rehpöhler <jens.rehpoehler@filoo.de> wrote:
> Hi all,
>
> todo i've done few performance tests with my two clusters.
>
> I've used : rados -p data load-gen --run-length 10 --target-throughput 50
>
> to generate some load. Now i have a question regarding "ceph -w" output.
>
> The output before the test was:
>
> 2012-01-18 11:55:28.621107    pg v113011: 594 pgs: 594 peering; 61022 MB
> data, 120 GB used, 244 GB / 372 GB avail
>
> here is the output after the test:
>
> 2012-01-18 13:53:30.190602    pg v113119: 594 pgs: 594 active+clean;
> 1058 GB data, 120 GB used, 244 GB / 372 GB avail
>
> How can i have more Data then the available discspace ? Is there any
> possiblity to identify the rados objects of this test and delete them
> manualy ?

A quick read of the source seems to say "rados load-gen" writes at
random offsets..

  size_t off = get_random(0, info.len);

which means you have a lot of sparse objects. And that makes the "1058
GB data, 120 GB used" make sense.
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