cloudstack/plugins
Remi Bergsma c0fde9a12b 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 <github@remi.nl>
2015-08-25 10:32:27 +02:00
..
acl/static-role-based Allow custom command role ACL files on classpath in Static Role API Checker. 2015-07-01 14:43:29 +02:00
affinity-group-processors Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
alert-handlers Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
api Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
database/mysql-ha CLOUDSTACK-8656: debug messages on interupted exceptions 2015-07-30 16:03:10 +02:00
dedicated-resources Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
deployment-planners Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
event-bus coverity 1291768: file input stream not severe unless repetitive (property file usually aren't) 2015-07-09 21:30:23 +02:00
file-systems/netapp Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
ha-planners/skip-heurestics Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
host-allocators/random Merge branch 'PR-REVIEW-335' 2015-07-06 11:48:38 +05:30
hypervisors Merge pull request #731 from remibergsma/centos7-kvm 2015-08-25 10:32:27 +02:00
network-elements Fix for the NicVO.java regression. 2015-08-21 14:03:00 +02:00
storage Merge pull request #654 from DaanHoogland/CLOUDSTACK-8656 2015-08-14 21:38:49 +02:00
storage-allocators/random Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00
user-authenticators More typos 2015-08-20 13:04:29 +01:00
pom.xml Updating pom.xml version numbers for release 4.5.2-SNAPSHOT 2015-05-07 15:33:01 +02:00