Bug 956683 – The default migration_max_bandwidth (32MiBps) & default max_outgoing_migrations (5) will saturate a 1Gbps link.

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Bug 956683 - The default migration_max_bandwidth (32MiBps) & default max_outgoing_migrations (5) will saturate a 1Gbps link.

Summary:	The default migration_max_bandwidth (32MiBps) & default max_outgoing_migratio...

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Virtualization Manager
Classification:	Red Hat
Component:	vdsm (Show other bugs)
Sub Component:
Version:	3.1.3
Hardware:	All All

Priority	unspecified Severity high
Target Milestone:	---
Target Release:	3.2.0
Assigned To:	Nobody's working on this, feel free to take it
QA Contact:
Docs Contact:

URL:
Whiteboard:	virt
Keywords:	ZStream

Depends On:
Blocks:	956724
	Show dependency tree / graph

Reported:	2013-04-25 08:37 EDT by Lee Yarwood
Modified:	2015-09-22 09 EDT (History)
CC List:	13 users (show)

See Also:
Fixed In Version:	vdsm-4.10.2-17.0.el6ev
Doc Type:	Bug Fix
Doc Text:	Previously, the default migration_max_bandwith (32MiBps) and the max_outgoing_migrations (5) saturated a 1Gbps link with migration traffic. This left no room for other kinds of traffic (for instance, management traffic). The max_outgoing_migrations default has been changed from 5 to 3. Migrations no longer saturate a 1Gbps link.
Story Points:	---
Clone Of:
Clones:	956724 (view as bug list)
Environment:
Last Closed:	2013-06-10 16:48:51 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
oVirt gerrit	14251	None	None	None	Never
Red Hat Product Errata	RHSA-2013:0886	normal	SHIPPED_LIVE	Moderate: rhev 3.2 - vdsm security and bug fix update	2013-06-10 20:25:02 EDT

Groups: None (edit)

Description Lee Yarwood 2013-04-25 08:37:07 EDT

Description of problem:
The default migration_max_bandwidth (32MiBps) & max_outgoing_migrations (5) will saturate a 1Gbps link.

Version-Release number of selected component (if applicable):
vdsm-4.10.2-16.0.el6ev

How reproducible:
Always.

Steps to Reproduce:
1. Start 5 or more migrations.
2. A typical 1Gbps link will become saturated with migration traffic.
  
Actual results:
1Gbps link saturated.

Expected results:
A 1Gbps link should not become saturated with migration traffic allowing room for management traffic etc.

Additional info:
BZ#925981 reverts vdsm to it's previous default behaviour of 32MiBps per migration but given the number of 5 out going migrations we can still saturate a typical 1Gbps link.

The real fix here is to dynamically calculate the bandwidth and number of migrations given the link speed to the migration network.

Comment 1 Andrew Cathrow 2013-04-25 09:17:01 EDT

So the action is to change the default form 5 to 3 concurrent

Comment 2 Michal Skrivanek 2013-04-25 09:33:55 EDT

target should be 3.2.0, the posted patch 7855 belongs to 3.1.z clone

Comment 4 Michal Skrivanek 2013-04-25 10:12:34 EDT

merged to master:
http://gerrit.ovirt.org/gitweb?p=vdsm.git;a=commit;h=a902734ff87f34b3066972ec47c7806d3acff005

Comment 7 Martin Pavlik 2013-05-02 09:07:30 EDT

works on SF15, max bandwidth usage during migration is approx 96MB/s

Comment 10 errata-xmlrpc 2013-06-10 16:48:51 EDT

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.

http://rhn.redhat.com/errata/RHSA-2013-0886.html

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