Bug 1392058

Summary:	[DOCS] Improve docs on utilization of NFS.
Product:	OpenShift Container Platform	Reporter:	Diógenes Rettori <drettori>
Component:	Documentation	Assignee:	Ashley Hardin <ahardin>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Liang Xia <lxia>
Severity:	medium	Docs Contact:	Vikram Goyal <vigoyal>
Priority:	medium
Version:	3.3.0	CC:	aos-bugs, bchilds, jokerman, jsafrane, mmccomas
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Last Closed:	2016-11-22 22:45:13 UTC	Type:	Bug
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Description Diógenes Rettori 2016-11-04 16:53:53 UTC

Document URL: 
https://docs.openshift.com/container-platform/3.3/install_config/aggregate_logging.html#pre-deployment-configuration

Section Number and Name: 
Persistent Elasticsearch Storage


Describe the issue: 
1- Remove information on performance: 'Performance under this solution is significantly worse than using actual local drives'.
This statement hasn't been verified and is causing confusion.

2- this text 'Using NFS storage as a volume or a persistent volume (or via NAS such as Gluster) is not supported for Elasticsearch storage, as Lucene relies on file system behavior that NFS does not supply. Data corruption and other problems can occur. If NFS storage is a requirement, you can allocate a large file on a volume to serve as a storage device and mount it locally on one host.' 
is misleading. 
First it says that NFS is not supported, then it explains how NFS can still be used. 


Suggestions for improvement: 

Additional information:

Comment 4 Jan Safranek 2016-11-16 15:13:43 UTC

(In reply to Diógenes Rettori from comment #0)
> Describe the issue: 
> 1- Remove information on performance: 'Performance under this solution is
> significantly worse than using actual local drives'.
> This statement hasn't been verified and is causing confusion.

Ack

> 2- this text 'Using NFS storage as a volume or a persistent volume (or via
> NAS such as Gluster) is not supported for Elasticsearch storage, as Lucene
> relies on file system behavior that NFS does not supply. Data corruption and
> other problems can occur. If NFS storage is a requirement, you can allocate
> a large file on a volume to serve as a storage device and mount it locally
> on one host.' 
> is misleading. 
> First it says that NFS is not supported, then it explains how NFS can still
> be used. 

Well, it says that NFS cannot be used as OpenShift PersistentVolume for ElasticSearch. And then it describes how to work around this by using a loopback device. This loopback must be maintained manually *outside of OpenShift*, i.e. on the node. You can't (or shouldn't) do it from inside a container.

Comment 5 Ashley Hardin 2016-11-16 22:18:11 UTC

@Jan, Thank you. I created a PR. PTAL:
https://github.com/openshift/openshift-docs/pull/3238

Comment 6 Liang Xia 2016-11-21 01:48:56 UTC

The PR looks good from QE's side.

Comment 7 openshift-github-bot 2016-11-21 12:33:45 UTC

Commits pushed to master at https://github.com/openshift/openshift-docs

https://github.com/openshift/openshift-docs/commit/e9cf80ddf08e98515ddc823b230622a875dc6fc1
Bug 1392058, clarified points around NFS storage

https://github.com/openshift/openshift-docs/commit/eccd3e8d15db325aa14931767ca0f7f2a653939f
Merge pull request #3238 from ahardin-rh/NFS-storage

Bug 1392058, clarified points around NFS storage

Comment 8 Ashley Hardin 2016-11-22 22:45:13 UTC

Content is now published:
https://access.redhat.com/documentation/en/openshift-container-platform/3.3/single/installation-and-configuration/#aggregated-elasticsearch