Bug 1589137

Summary:	RFE: Separate unrecommended and unsupported items into two installer flags
Product:	OpenShift Container Platform	Reporter:	François Cami <fcami>
Component:	Image Registry	Assignee:	Ben Parees <bparees>
Status:	CLOSED ERRATA	QA Contact:	Wenjing Zheng <wzheng>
Severity:	low	Docs Contact:
Priority:	unspecified
Version:	3.11.0	CC:	agladkov, aos-bugs, bleanhar, clichybi, dmoessne, erich, jokerman, mmccomas, obulatov, tkatarki, william.caban, xtian
Target Milestone:	---
Target Release:	3.11.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-10-11 07:20:33 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description François Cami 2018-06-08 13:15:15 UTC

Description of problem:

The installer flag openshift_enable_unsupported_configurations 
is now used for both unsupported and not recommended configurations.

It would be worth splitting this to:
openshift_enable_unsupported_configurations 
openshift_enable_unrecommended_configurations 
to eliminate confusion.

Comment 9 Ben Parees 2018-06-18 16:05:36 UTC

Alexey/Oleg:  Is there any historical reason why NFS is supported but not recommended (Assuming that is an accurate description of the current state)?  It sounds like there may have been some performance concerns?  Is there a performance test our performance team could do that would convince us whether or not those concerns are still valid?

Comment 10 Alexey Gladkov 2018-06-18 20:05:21 UTC

(In reply to Ben Parees from comment #9)
> Alexey/Oleg:  Is there any historical reason why NFS is supported but not
> recommended (Assuming that is an accurate description of the current state)?

I heard a list of supported backends from Clayton and this list repeats what is written in the documentation and is quoted here. I mean:

- Filesystem.
  - Local filesystem.
  - GlusterFS Storage.
  - Ceph Rados Block Device.
- S3.
- OpenStack Swift
- Google Cloud Storage (GCS)
- Microsoft Azure
- Aliyun OSS

As far as I remember, we do not support NFS also because the mountpoint can get into the stale state. But I'm afraid to say something here because I did not study this question.

> It sounds like there may have been some performance concerns?

Maybe. No one studied this question and no one tested it. Perhaps there may be technical problems in the container, for example, after restarting the nfs-server.

> Is there a
> performance test our performance team could do that would convince us
> whether or not those concerns are still valid?

I do not have any information whether they have any tests at all, how often these tests are performed. I have never seen the results of these tests.
I do not even know who does this in this team.

Therefore, I can not answer these questions.

Comment 23 William Caban 2018-07-18 23:30:12 UTC

According to the documentation we do support NFS as a storage backend for the registry:

https://docs.openshift.com/container-platform/3.9/install_config/install/advanced_install.html#advanced-install-registry

But in the same document, at the end of the NFS config options, in the upgrades section, we have this message: 

"The use of NFS for the core OpenShift Container Platform components is not recommended, as NFS (and the NFS Protocol) does not provide the proper consistency needed for the applications that make up the OpenShift Container Platform infrastructure."

Can't we use this same message for the upgrades/installs to avoid confusion?

Comment 24 Eric Rich 2018-07-19 14:08:42 UTC

Related work in this area: https://bugzilla.redhat.com/show_bug.cgi?id=1416639

Comment 25 Ben Parees 2018-07-20 17:05:03 UTC

PR to add a warning: https://github.com/openshift/openshift-ansible/pull/9271

Comment 26 Wenjing Zheng 2018-08-23 08:44:55 UTC

I can see the warning as below with 3.11.0-0.20.0:
Hosted Install              : Complete (0:02:27)
	The use of NFS for the core OpenShift Container Platform components is not recommended, as NFS (and the NFS Protocol) does not provide the proper consistency needed for the applications that make up the OpenShift Container Platform infrastructure.

Comment 28 errata-xmlrpc 2018-10-11 07:20:33 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:2652

Comment 29 Red Hat Bugzilla 2023-09-15 00:09:55 UTC

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 500 days