Manage a Host

On the main menu of ZStack Cloud, choose Resource Center > Hardware > Computing Facility > Host. Then, the Host page appears.

The following table lists the actions that you can perform on a host.
Action Description Preconditioned Host Status
Add Host Add one or more hosts. /
Edit Host Edit the name and description of a host. /
Enable Host Enable a host. Disabled
Disable Host Disable a host.
Note: Disabling a host does not affect the resources already running on the host. However, the host is no longer available as a candidate when you apply for new resources.
 Enabled
Reconnect Host Reconnect a host.
Note: In most cases, host reconnection can be implemented when the host configurations are updated. For example, if the memory or volume capacity of a hots is updated, you can reconnect the host to update the database.
 ALL
Enter Maintenance Mode Enter the maintenance mode. If a host is in maintenance mode, you can power off the host or troubleshoot failures.
  • If the primary storage is of the LocalStorage type, VM instances on a host are stopped when the host enters maintenance mode.
  • If the primary storage is of a shared storage type, VM instances on a host are automatically migrated when the host enters maintenance mode.
Note: If the primary storage is of a shared storage type, you can configure the policy on failures of VM migration triggered when the host enters maintenance mode.
On the main menu of ZStack Cloud, choose Settings > Platform Setting > Global Setting > Advanced > Host, and configure the Policy for VM Migration Failure in Entering Host Maintenance Mode setting:
  • StopVmOnMigrationFailure: When the host enters maintenance mode, VM instances are automatically migrated to another host. If a VM instance fails to be migrated, the VM instance is forcibly stopped.
  • JustMigrate: When the host enters maintenance mode, VM instances are automatically migrated to another host. If a VM instance still runs on the host, the host fails to enter the maintenance mode.
 Connected
Attach Tag Attach a tag to one or more hosts.
Note:
  • You can attach a maximum of 50 tags to a resource. The number of resources to which a tag can be attached is not limited.
  • You can attach one or more tags to one or more resources.
  • A tag created by a tenant can be attached only to the resources owned by the tenant. The admin can attach a tag to all resources.
  • The admin can detach or delete tags created by a tenant.
  • You can sort tags attached to resources by attachment time or tag name. Tag names are sorted based on symbols, digits, Chinese letters, and English letters in descending order. To configure the sorting method, go to the main menu of ZStack Cloud, choose Settings > Platform Setting > Global Setting > Basic, and then configure the Tag Sort Method setting. By default, resources are sorted by tag name.
 ALL
Detach Tag Detach a tag from a host.
Note:
  • The admin tags are created and owned by the admin. The tenant tags are created and owned by tenants.
  • A tag created by a tenant can be attached only to the resourced owned by the tenant. The admin can attach a tag to all resources.
  • The admin can detach or delete tags created by a tenant.
  • Tags created in a project belongs to the project. All project members, including the project admin, project managers, and normal project members, can perform actions on the tags.
  • You cannot change the owner of a tag.
  • If you change the owner of a resource, all tenant tags attached to the resource are detached. The admin tags are not affected.
  • After a seamless migration of the cloud platform, tags that were created are automatically updated and displayed in the latest format. If an error or exception occurs, refresh the browser or create a new tag.
  • You can detach a batch of tags from a resource or detach a tag from a batch of resources.
  • A tenant can only detach tags from resources owned by the tenant. The admin can detach tags from all resources.
 ALL
Update Password Update the password of a host. After the password is updated, the host is automatically reconnected. /
Delete Host Delete a host.
Note: If you delete a host, note that:
  • Deleting a host stops all VM instances running on the host.
  • If a LocalStorage primary storage is attached to the cluster to which the host belongs:
    • Deleting a host deletes all VM instances and volumes on the host.
    • If you add the deleted host to the cloud platform, the system redeploys the host. If you did not backup the database, the related business data cannot be recovered.
  • If a shared primary storage is attached to the cluster to which the host belongs:
    • If you disable HA for VM instances:

      Deleting a host stops the VM instances running on the host.

    • If you enable HA for VM instances:

      Deleting a host stops the VM instances for which HA is enabled and then migrates the VM instances to other hosts where resources are available. Then the VM instances are automatically started. During the process, data security is not affected. If host resources are insufficient, the VM instances are stopped upon the host deletion.

    • Deleting a host does not affect data volumes stored on shared storages.
  • If a host is designated as the migration server, deleting a host also deletes the migration server and the migration task on the migration server will be cancelled. Proceed with caution.
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