Bug 1229204

Summary:	VDSM service is not running without mom in RHEL-7
Product:	[Retired] oVirt	Reporter:	Ramesh N <rnachimu>
Component:	vdsm	Assignee:	Martin Sivák <msivak>
Status:	CLOSED WONTFIX	QA Contact:	Shira Maximov <mshira>
Severity:	urgent	Docs Contact:
Priority:	urgent
Version:	3.5	CC:	barumuga, bazulay, bugs, dfediuck, ecohen, gklein, istein, lsurette, mgoldboi, nlevinki, rbalakri, rgolan, rhs-bugs, rhsc-qe-bugs, rnachimu, shtripat, yeylon
Target Milestone:	---
Target Release:	3.5.5
Hardware:	Unspecified
OS:	Linux
Whiteboard:	sla
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1229202	Environment:
Last Closed:	2015-08-24 11:18:13 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	SLA	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1229202

Description Ramesh N 2015-06-08 09:22:07 UTC

+++ This bug was initially created as a clone of Bug #1229202 +++

Description of problem:

VDSM service gets killed immediately after start in mom package is not installed. 

Version-Release number of selected component (if applicable):

vdsm-4.17.0-766.git2bf570a.el7.x86_64

How reproducible:

Always
Steps to Reproduce:
1. Start the VDSM Service by 'service vdsmd start'
2. Check the vdsm service status 'service vdsmd status'

Actual results:
  VDSM service will be in inactive or failed status.

Expected results:

VDSM service should be running without mom. 

Additional info:
Red Hat Gluster Storage build of VDSM doesn't require MOM as a dependency and vdsmd should run without mom. Also in RHEL-6 VDSM works without mom.

--- Additional comment from Red Hat Bugzilla Rules Engine on 2015-06-08 05:19:50 EDT ---

This bug is automatically being proposed for Red Hat Gluster Storage 3.1.0 by setting the release flag 'rhgs‑3.1.0' to '?'. 

If this bug should be proposed for a different release, please manually change the proposed release flag.

--- Additional comment from Ramesh N on 2015-06-08 05:20:19 EDT ---

Comment 1 Martin Sivák 2015-06-11 11:58:29 UTC

There is a very interesting sequence of actions that is causing this when MOM is not available:

1) systemd starts vdsmd service and makes sure that ksmtuned.service is not running (vdsmd.service contains Conflicts=libvirt-guests.service ksmtuned.service)
2) vdsmd detects that mom is not available and falls back to ksmMonitor (vdsm/ksm.py)
3) ksmMonitor tries to make sure both ksmd and ksmtuned are running (ksm.py:68 and 106)
4) systemd starts preparing ksmtuned start and finds out that vdsmd has a conflict with it
5) ksmtuned's start was requested later than vdsmd and so ksmtuned wins
6) systemd kills vdsmd and starts ksmtuned

Comment 2 Bala.FA 2015-06-11 12:34:45 UTC

Few thoughts here.

1. Are mom and ksmtuned conflicting services?  If not,  I feel vdsmd can set priority to mom if not available it can do with ksmtunded.

2. I think removing ksmtuned.service from vdsmd.service.in would help as workaround.

Comment 3 Martin Sivák 2015-06-15 07:07:41 UTC

1) Yes, those are conflicting.
2) Yes, it does help as a workaround.

Comment 4 Bala.FA 2015-06-15 07:59:35 UTC

I believe right fix would be setting 'conflicts: ksmtuned.service' in mom.service.  vdsmd is not the right service for setting conflicts wrt to this.

Comment 5 Ilanit Stein 2015-06-16 15:27:11 UTC

bug verification steps:
Deploy a host, remove mom package using rpm -e --nodeps and restart vdsmd

Comment 6 Roy Golan 2015-08-19 13:38:46 UTC

in 3.5 mom can't be removed from vdsm. in 3.6 mom was separated completely from vdsm. See Bug 1227714.

Comment 7 Roy Golan 2015-08-24 11:18:13 UTC

mistakenly changed.

Comment 8 Ramesh N 2015-09-28 11:45:41 UTC

(In reply to Roy Golan from comment #6)
> in 3.5 mom can't be removed from vdsm. in 3.6 mom was separated completely
> from vdsm. See Bug 1227714.

OK. Not a problem.