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https://issues.apache.org/jira/browse/CLOUDSTACK-8625?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14710881#comment-14710881
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ASF subversion and git services commented on CLOUDSTACK-8625:
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Commit c0fde9a12bf32d0d4009792d05b1648f7c6ea419 in cloudstack's branch
refs/heads/master from [~remibergsma]
[ https://git-wip-us.apache.org/repos/asf?p=cloudstack.git;h=c0fde9a ]
Merge pull request #731 from remibergsma/centos7-kvm
CLOUDSTACK-8443: Support CentOS 7 as KVM hypervisorThis adds support for CentOS
7 as a KVM hypervisor. As discussed in the Jira issue, the root cause of the
issue was the `cloudstack-setup-agent` script that added this line to
`/etc/libvirt/qemu.conf`:
`cgroup_controllers=["cpu"]`
On CentOS 6 this 'works', but since by default no cgroups are mounted, this
setting is ignored by `libvirtd`. On CentOS 7 is does not work, because the
`cpu` and `cpuacct` are 'co-mounted'. This simpy means you cannot use one
without the order. The config line above instructs `libvirtd` to only use the
`cpu` cgroup, which it can't.
There was code added to make sure the `cpu` cgroup was not co-mounted. It did
this with a shell script, but after a reboot it was gone. It wasn't reliable
and not even a solution at all. I went ahead and removed the code, because the
co-mounted cgroups work fine. The real issue was the config line we put in
`/etc/libvirt/qemu.conf` so much better to fix that instead.
The default for `libvirtd` is to use only cgroups that are mounted. When you
remove the 'cgroup_controllers' line, the default kicks in. According to the
`qemu.conf` file, the default is:
`cgroup_controllers = ["cpu", "devices", "memory", "blkio", "cpuacct",
"net_cls"]`
Then again, if it's not mounted, it's not used. So, that's a nice way to
control it.
This works just fine for both RHEL/CentOS 6 and RHEL/CentOS 7.
Along the debugging, I came across some small issues here and there which I
also fixed in this PR.
If you test this, be sure to build RPMs from this branch and install those on
the KVM hypervisor.
At Schuberg Philis we run KVM hypervisors on CentOS 7 for months with these
fixes. Now I took the time to fix the issues in CloudStack, rather than work
around them.
@bhaisaab @karuturi could you please review this? Thanks!
Please note:
The next step is to fix CLOUDSTACK-8625 (Systemd profile for KVM Agent) as
currently a sysvinit script is still used. Although it works, we do not have
any systemd benefits. As it is a separate issue, I'll try to address it in a
separate PR.
* pr/731:
CLOUDSTACK-8443: detect CentOS 7.x as RHEL 7 alike
CLOUDSTACK-8443: mention the correct logfile
CLOUDSTACK-8443: display the right hypervisor type
CLOUDSTACK-8443: don't try to fix co-mounted cgroups
Signed-off-by: Remi Bergsma <[email protected]>
> Systemd profile for KVM Agent
> -----------------------------
>
> Key: CLOUDSTACK-8625
> URL: https://issues.apache.org/jira/browse/CLOUDSTACK-8625
> Project: CloudStack
> Issue Type: Improvement
> Security Level: Public(Anyone can view this level - this is the
> default.)
> Components: KVM
> Environment: Ubuntu 16.04, CentOS 7.X
> Reporter: Wido den Hollander
> Labels: agent, kvm, systemd
> Fix For: Future
>
>
> We currently only support sysvinit, but with CentOS and Ubuntu both moving to
> Systemd we should support systemd.
> To do this we can:
> - Loose JSVC
> - Log to stdout and let systemd / journalctl handling the logging
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