Bug 1872860

Summary:	[Docs] Add clarity text for MON requirements
Product:	[Red Hat Storage] Red Hat OpenShift Container Storage	Reporter:	khartsoe <khartsoe>
Component:	documentation	Assignee:	Disha Walvekar <dwalveka>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Sidhant Agrawal <sagrawal>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	4.4	CC:	asriram, dwalveka, ebenahar, nberry, ocs-bugs, tnielsen
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Last Closed:	2020-10-19 06:50:03 UTC	Type:	Bug
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Bug Blocks:	1885167

Description khartsoe@redhat.com 2020-08-26 18:33:14 UTC

Describe the issue:
Per https://access.redhat.com/support/cases/#/case/02720671 , customer was unclear whether they needed to create a separate PV for MON's. 

In 4.4, MONs use the `monDataDirHostPath` and do not need a PV. 

Describe the task you were trying to accomplish:
Preparing environment for deploying OCS 4.4.

Suggestions for improvement:
Recommend adding the following statement for clarity in order to prevent future confusion:

"You do not need to use a separate PV for MONs"



Document URL:
https://access.redhat.com/documentation/en-us/red_hat_openshift_container_storage/4.4/html-single/planning_your_deployment/index#node_requirements

Chapter/Section Number and Title:
3.1 Node Requirements 
Add statement as a sub-bullet under "MON will use 10 GiB storage space under /var/lib/rook for local storage deployments." (in "Table 3.2. Minimum requirements for starter nodes"

Product Version:
4.4

Environment Details:
N/A

Any other versions of this document that also needs this update:
No

Additional information:
No

Comment 3 Travis Nielsen 2020-10-06 16:38:37 UTC

There are two methods of installation for the mons in OCS:
1. monDataDirHostPath: We will use approximately 10GB of storage under the /var/lib/rook path on the host.
2. monPVCTemplate: If a PVC template is specified, then three PVs are required for mons on the hosts where the mons will run. 

For bare metal, option 1 is recommended to avoid creating PVs on disks that could otherwise be used for OSDs.

Does this clarify?

Comment 4 Neha Berry 2020-10-07 07:56:36 UTC

(In reply to Travis Nielsen from comment #3)
> There are two methods of installation for the mons in OCS:
> 1. monDataDirHostPath: We will use approximately 10GB of storage under the
> /var/lib/rook path on the host.
> 2. monPVCTemplate: If a PVC template is specified, then three PVs are
> required for mons on the hosts where the mons will run. 
> 
> For bare metal, option 1 is recommended to avoid creating PVs on disks that
> could otherwise be used for OSDs.
> 
> Does this clarify?

Hi Travis,

yes we document only #1 and hence via this bug, we wanted to add a suggestion like this. Does "You do not need to use a separate PV for MONs" statement convey the message. IMO, "separate PV" might imply we will use "same PV" should we write as ""You do not need to use PVs for MONs" ? WDYT ?


From COmment#0
++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Suggestions for improvement:
Recommend adding the following statement for clarity in order to prevent future confusion:

"You do not need to use a separate PV for MONs"
++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Comment 5 Travis Nielsen 2020-10-08 18:47:17 UTC

What about this? 

10 GiB storage per MON on all the storage nodes.
- MON will use 10 GiB storage space on the host under /var/lib/rook for local storage deployments. No PV is necessary for MONs.

Comment 6 Neha Berry 2020-10-09 08:20:42 UTC

(In reply to Travis Nielsen from comment #5)
> What about this? 
> 
> 10 GiB storage per MON on all the storage nodes.
> - MON will use 10 GiB storage space on the host under /var/lib/rook for
> local storage deployments. No PV is necessary for MONs.

Ack

@disha can you make this change and add the preview link so that the BZ can be verified?