Red Hat Bugzilla – Bug 865347
RFE: Hypervisor installer should change host's IO scheduler to deadline for improved performance
Last modified: 2016-04-26 18:11:41 EDT
Description of problem:
The IO performance of VMs when running on a host with the IO scheduler set as deadline is better than when running with the default scheduler (CFQ). The os-installer should change the IO scheduler.
Just add elevator=deadline to the kernel args.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
Perf team used to have a tool called tuna that made it possible to apply profiles to hosts, and one of the profiles was for a 'kvm host'
@mwagner, can you assist with info here?
(In reply to comment #2)
> Perf team used to have a tool called tuna that made it possible to apply
> profiles to hosts, and one of the profiles was for a 'kvm host'
> @mwagner, can you assist with info here?
I thought Packstack was going to use otopi/ovirt-host-deploy.
It's available there:
Hi, tuned is a user space package that controls the profiles. There are profiles for virtual-host and virtual-guest amongst others. It should be possible to install and configure the use of the virtual-host profile.
Note that tuna is a different tool.
I have to translate this into a equivalent puppet manifest but would something like this be appropriate ?
if ! tuned-adm active | grep virtual-host 2> /dev/null ; then
tuned-adm profile virtual-host
This probably changes more then just the IO scheduler but its all good stuff right?
Also does this changed persist on reboot?
Fix submitted upstream
Verified NVR: openstack-packstack-2012.2.3-0.1.dev454.el6ost.noarch
1. Verified that 'tuned-adm active | grep virtual-host' returned no output.
2. Used packstack to install openstack.
3. Verified Active Profile again:
# tuned-adm active | grep virtual-host
Current active profile: virtual-host
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.