深入了解kolla实现，以及更改docker的一些配置。

Kolla

  • Kolla的配置文件都存放在/etc/kolla/，当容器启动时，会读取这里的配置。
  • Kolla-ansible则提供了类似模板的办法去修改配置文件，并分发到各个node上。

An operator can change the location where custom config files are read from by editing /etc/kolla/globals.yml and adding the following line.
The directory to merge custom config files the kolla’s config files
node_custom_config: “/etc/kolla/config”
Kolla allows the operator to override configuration of services. Kolla will look for a file in /etc/kolla/config/<< service name >>/<< config file >>. This can be done per-project, per-service or per-service-on-specified-host.
If the operator wants to configure compute node cpu and ram allocation ratio on host myhost, the operator needs to create file /etc/kolla/config/nova/myhost/nova.conf with content:
Kolla allows the operator to override configuration globally for all services. It will look for a file called /etc/kolla/config/global.conf.
For example to modify database pool size connection for all services, the operator needs to create /etc/kolla/config/global.conf with content:

Overcommitting

  • 尝试修改Openstack overcommitting参数，实际上默认值已经超卖了资源，cpu 16:1，memory 1.5:1。

  • nova-scheduler.conf

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    [DEFAULT]
    cpu_allocation_ratio = 2.0
    enabled_filters = AggregateInstanceExtraSpecsFilter, RetryFilter, AvailabilityZoneFilter, RamFilter, DiskFilter, ComputeFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter, CoreFilter

Docker

  • kolla的持久化文件，都在docker根目录下的volumes，很容易就能看懂。

  • 虚拟机就是volumes/nova_compute/_data/instances。

  • 因此，docker根目录的磁盘空间要足够，最好的办法是直接mount一块区域给/var/lib/docker。

  • 但我们已经分配好了所有的磁盘，并且都是xfs，调整并不方便。

  • 先停止docker daemon，将根目录迁移，然后创建一个soft link，完成偷梁换柱。

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    mv /var/lib/docker /home/lib/docker
    link -s /home/lib/docker /var/lib/docker

Reference