Bug 1579758 - Converting to replica 2 volume is not throwing warning
Summary: Converting to replica 2 volume is not throwing warning
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Gluster Storage
Classification: Red Hat Storage
Component: replicate
Version: rhgs-3.4
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
: RHGS 3.4.z Batch Update 2
Assignee: Ravishankar N
QA Contact: Anees Patel
URL:
Whiteboard:
Depends On: 1627044
Blocks:
TreeView+ depends on / blocked
 
Reported: 2018-05-18 09:16 UTC by Vijay Avuthu
Modified: 2018-12-17 17:07 UTC (History)
9 users (show)

Fixed In Version: glusterfs-3.12.2-27
Doc Type: Release Note
Doc Text:
Previously, users were prompted with a warning message (‘replica 2 configurations can lead to split brain’) only while creating replica 2 volumes. With this update, users are now warned about the limits of replica 2 configurations when converting any other type of volume to replica 2 configuration using add-brick or remove-brick options.
Clone Of:
: 1627044 (view as bug list)
Environment:
Last Closed: 2018-12-17 17:07:02 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2018:3827 0 None None None 2018-12-17 17:07:17 UTC

Description Vijay Avuthu 2018-05-18 09:16:38 UTC
Description of problem:

Converting to replica 2 volume is not throwing warning

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

glusterfs-3.12.2-10.el7rhgs.x86_64

How reproducible:

Always

Below Scenarios was not throwing Warning while converting to replica 2

1) while converting distribute only to x2
2) while removing bricks from x3 to convert to x2
3) while adding/removing bricks in x2 configurations

Actual results:

Doesn't show any warning while doing above scenarios

Expected results:

Expecting to throw warning like below

" Replica 2 volumes are prone to split-brain. Use Arbiter or Replica 3 to avoid this.
Do you still want to continue?
 (y/n) y
"

Additional info:

Comment 4 Karthik U S 2018-09-11 08:35:15 UTC
Upstream patch: https://review.gluster.org/#/c/glusterfs/+/21136/

Comment 12 Anees Patel 2018-11-13 09:06:26 UTC
Verified the fix on 3.4.z Batch 2 update.
# rpm -qa | grep gluster
glusterfs-api-3.12.2-27.el7rhgs.x86_64
tendrl-gluster-integration-1.5.4-14.el7rhgs.noarch
glusterfs-client-xlators-3.12.2-27.el7rhgs.x86_64
glusterfs-events-3.12.2-27.el7rhgs.x86_64
gluster-nagios-addons-0.2.10-2.el7rhgs.x86_64
glusterfs-fuse-3.12.2-27.el7rhgs.x86_64

I am able to get the warning "Replica 2 volumes are prone to split-brain. Use Arbiter or Replica 3 to avoid this."  for the below scenarios

1) while converting distribute only to x2
2) while removing bricks from x3 to convert to x2
3) while adding/removing bricks in x2 configurations

Hence changing this to verified

Comment 13 Anees Patel 2018-11-22 17:48:27 UTC
Test-coverage is achieved by adding necessary "split-brain prone" warning check on existing remove-brick/add brick test-cases.

Comment 14 Anjana KD 2018-12-04 10:40:57 UTC
Updated the Doc text field. Kindly review for technical accuracy.

Comment 15 Karthik U S 2018-12-04 11:09:29 UTC
(In reply to Anjana from comment #14)
> Updated the Doc text field. Kindly review for technical accuracy.

LGTM.

Comment 16 errata-xmlrpc 2018-12-17 17:07:02 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-2018:3827


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