Bug 925981 - default migration bandwidth capping is not honored anymore
Summary: default migration bandwidth capping is not honored anymore
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Virtualization Manager
Classification: Red Hat
Component: vdsm
Version: 3.1.3
Hardware: Unspecified
OS: Unspecified
urgent
medium
Target Milestone: ---
: 3.2.0
Assignee: Saveliev Peter
QA Contact: Pavel Stehlik
URL:
Whiteboard: virt
: 948353 (view as bug list)
Depends On: 948821
Blocks: 950603
TreeView+ depends on / blocked
 
Reported: 2013-03-23 03:00 UTC by Nandini Chandra
Modified: 2022-07-09 07:05 UTC (History)
17 users (show)

Fixed In Version: vdsm-4.10.2-16.0.el6ev
Doc Type: Bug Fix
Doc Text:
Previously, libvirt changed the default behaviour from the limited migration bandwidth to unlimited one. This meant that without any migration bandwidth limitation, the network could be saturated during mass migrations. The default limit was set to "on". This solution is compatible with all versions, and preserves the original behaviour. This fix ensures that customers with large networks will notice no change in migration behavior.
Clone Of:
: 950603 (view as bug list)
Environment:
Last Closed: 2013-06-10 20:46:30 UTC
oVirt Team: ---
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Issue Tracker RHV-47298 0 None None None 2022-07-09 07:05:26 UTC
Red Hat Knowledge Base (Solution) 344073 0 None None None Never
Red Hat Product Errata RHSA-2013:0886 0 normal SHIPPED_LIVE Moderate: rhev 3.2 - vdsm security and bug fix update 2013-06-11 00:25:02 UTC
oVirt gerrit 13781 0 None None None Never

Description Nandini Chandra 2013-03-23 03:00:41 UTC
Description of problem:
The /usr/share/doc/<vdsm-version>/vdsm.conf.sample file has the following information.
# Maximum bandwidth for migration, in mbps, 0 means libvirt's default
# (30mbps?).
# migration_max_bandwidth = 0

In RHEL 6.4 with libvirt-0.10.2-18,the maximum available bandwidth is used by default for migration of KVM guests.So,this needs to be changed to reflect the change made in libvirt.

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


How reproducible:


Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:


Additional info:

Comment 1 Nandini Chandra 2013-03-23 03:02:58 UTC
http://libvirt.org/git/?p=libvirt.git;a=commitdiff;h=6cfdeaac552e1ef744f269ed4cef3d74e663d677

With this commit,the default maximum migration bandwidth of 32 Mb/s in the older versions of libvirt has been removed and in 
RHEL 6.4/libvirt-0.10.2-18.el6.x86_64.rpm,the maximum available bandwidth is used by default for migration of KVM guests.

-Nandini

Comment 2 Michal Skrivanek 2013-04-04 16:14:56 UTC
*** Bug 948353 has been marked as a duplicate of this bug. ***

Comment 3 Michal Skrivanek 2013-04-04 16:25:55 UTC
This can cause overload of network interfaces as the whole bandwidth is used in case of mass migration (either manual or induced by moving a host to maintenance mode) 

The fix would be to use the former 30Mbps value as the default in vdsm config.
something like:
-        ('migration_max_bandwidth', '0',
-            'Maximum bandwidth for migration, in mbps, 0 means libvirt\'s '
-            'default (30mbps?).'),
+        ('migration_max_bandwidth', '32',
+            'Maximum bandwidth for migration, in Mbps, 0 means unlimited, former libvirt\'s '
+            'default is 32Mbps.'),

plus we need to fix upgrade as well, I guess

Comment 10 Saveliev Peter 2013-04-11 07:36:50 UTC
merged as ovirt:9974c596737c5f59ad6c2add02111efc12cb1d1c

preparing backports

Comment 21 errata-xmlrpc 2013-06-10 20:46:30 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.

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


Note You need to log in before you can comment on or make changes to this bug.