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Bug 1634682

Summary:	lvcache cockpit section should input the target LV to be cached, in case of thick LV is chosen for brick
Product:	[oVirt] cockpit-ovirt	Reporter:	SATHEESARAN <sasundar>
Component:	Gdeploy	Assignee:	Parth Dhanjal <dparth>
Status:	CLOSED DEFERRED	QA Contact:	SATHEESARAN <sasundar>
Severity:	high	Docs Contact:
Priority:	medium
Version:	0.11.29	CC:	bugs, dparth, godas, guillaume.pavese, sabose
Target Milestone:	---	Flags:	sasundar: ovirt-4.3?
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-03-27 08:04:17 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Gluster	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1608268

Description SATHEESARAN 2018-10-01 11:10:20 UTC

Description of problem:
------------------------
Choosing the thinp LV or thick LV, is currently not the user choice in cockpit UI. By default, the thinp LV is chosen. But there is a existing bug ( BZ 1600156 ), which disallows using thinp with dm-thinpool. So when dedupe & compression is enabled on the brick, automatically the brick is chosen as 'thick' LV

In this case, when user preferts to have lvcache feature, the user need to provide the target LV that has to be cached. Without this target LV to be cached, it makes no sense to create 'lvmcache'

Version-Release number of selected component (if applicable):
--------------------------------------------------------------
RHHI 1.1 / 2.0

How reproducible:
-----------------
Always

Steps to Reproduce:
-------------------
1. Choose to enable dedupe and compression on the bricks from cockpit UI
2. Enable lvcache feature

Actual results:
---------------
Fails to enable lvcache feature

Expected results:
-----------------
lvcache should be enabled for a target LV

Additional info:

Comment 1 Sandro Bonazzola 2019-01-28 09:44:01 UTC

This bug has not been marked as blocker for oVirt 4.3.0.
Since we are releasing it tomorrow, January 29th, this bug has been re-targeted to 4.3.1.

Comment 2 Guillaume Pavese 2019-02-27 14:34:50 UTC

This was pushed to ovirt-4.3.3 but was it not meant to be 4.3.2?
Asking because I am particularly waiting for this feature to deploy production

Comment 3 Parth Dhanjal 2019-03-12 07:06:30 UTC

(In reply to Guillaume Pavese from comment #2)
> This was pushed to ovirt-4.3.3 but was it not meant to be 4.3.2?
> Asking because I am particularly waiting for this feature to deploy
> production

Can you please elaborate on your requirement?
Maybe we can figure a work-around it.

Comment 4 Guillaume Pavese 2019-03-13 08:46:03 UTC

Hi, we have abandoned Gluster/Hyperconverged and will setup HE on iSCSI

We were awaiting LV Cache for thick provisioning as we were expecting to use VDO (forced on Thick P currently) on RAID5 HDD + SSD Cache
But it was not clear anyway that LV Cache was performing as promised ; as asked by a RedHat engineer (Leif Madsen , who did not get an answer to his question) on BZ 1608268. So we were not confident enough in the end.

Comment 5 SATHEESARAN 2019-03-27 08:03:30 UTC

(In reply to Guillaume Pavese from comment #4)
> Hi, we have abandoned Gluster/Hyperconverged and will setup HE on iSCSI
> 
> We were awaiting LV Cache for thick provisioning as we were expecting to use
> VDO (forced on Thick P currently) on RAID5 HDD + SSD Cache
> But it was not clear anyway that LV Cache was performing as promised ; as
> asked by a RedHat engineer (Leif Madsen , who did not get an answer to his
> question) on BZ 1608268. So we were not confident enough in the end.

Hi,

You can use the updated VDO systemd unit file as per the article[1], that fixes this problem.
This will enable discards to work with VDO & thinpool

[1] - https://access.redhat.com/solutions/3562021

Comment 6 SATHEESARAN 2019-03-27 08:04:17 UTC

This fix is not really required, as the thinpool can now be supported on top of VDO