VM Placement Rules

VM Placement Rules Overview

Zadara Cloud Services enables rules creation which determines how the VMs used by projects should be placed on the physical nodes of clusters.

Defining a rule is a 3-stage process.

  1. First, using the tags attached to the VMs and nodes, choose the placement rule type and set its parameters. There are three placement rule types from which to choose:

    1. Same tagged-VM rule - Placement of the VMs is a function of the common specific tag that they share.

    2. Different-tagged VM rule - Placement of the VMs is a function of the different tags with which each VM was marked.

    3. VM and Node tags - Placement of the VMs is a function of the specific tags with which the VM and its host Node were marked.

    Note

    The VM and Node tags rule, can be created only by an Admin user.

  2. After determining the rule type and setting its specific parameters, define the level of its enforcement. There are two options:

    1. Hard - VMs will be created only within the rule’s constraints.

    2. Soft - The VMs will be created even if Zadara Cloud Services does not succeed to place the VMs according to the rule’s constraints.

  3. Finally, determine the scope of this rule, if this is a system-wide rule or only for a specific project. Note: This third stage is only for an admin user. The scope of a VM Placement Rule for a regular member user is automatically determined as that of the currently displayed project.

VM Placement Rules

  1. Go to the Compute > Rules view. A list of all VM Placement Rules is displayed.

  2. The following information is displayed for each rule:

    1. Description

    2. Tags used

    3. Enforcement level

    4. Scope

    5. Enabled

    6. Creation Date

  3. The following Placement Rule actions can be performed from this view:

    1. Add a Rule

  4. Additional actions which can be performed from this view once a Project has been selected are:

    1. Simulate a Rule

    2. Apply a Rule

    3. Remove a Rule

Creating a VM Placement Rules

Zadara Cloud Services enables rules creationn which determine how the VMs used by projects should be placed on the physical nodes of clusters.

To create a VM Placement Rule

  1. Go to the ComputeRules view.

    1. Click Add Rule. The Create VM Placement Rule window is displayed.

  2. Do the following:

    1. Select the type of VM Placement Rule needed and define its parameters.

    Note

    Select existing tags or create new tags in any of the Tag fields.

    1. Determine whether the enforcement of the rule should be Hard or Soft.

    2. Define the scope of this rule, either system-wide or for a specific project. Note: This third step is required only by an admin user. The scope of a VM Placement Rule for a regular member user is automatically determined as that of the currently displayed project.

  3. Click OK - The new VM Placement Rule will appear on the Rules view.

Note

Create as many VM Placement Rules as wanted, provided that the rule does not either duplicate, contradict or override any other rule, or that it itself is not overridden by any other rule.

Simulating a VM Placement Rule

  1. Go to the Compute > Rules view. A list of the VM placement rules is displayed. Note: ‘Admin’ users can view the list with all of the rules in the cluster. ‘Member’, ‘Tenant Admin’ or ‘Read Only Admin’ users, can view the list with only those rules associated with the currently displayed projects listed .

  2. Highlight the row of the placement rule to simulate. A Simulate Rule button appears in the toolbar.

  3. Click Simulate Rule. The Simulate Rule information window, which informs about which instances will be potentially affected by the rule, appears.

  4. Click OK.

Applying a VM Placement Rule

  1. Go to the Compute > Rules view. A list of the VM placement rules is displayed. Note: ‘Admin’ users can view the list with all of the rules in the cluster. ‘Member’, ‘Tenant Admin’ or ‘Read Only Admin’ users, can view only those rules associated with the currently displayed projects listed.

  2. Highlight the row of the placement rule to apply. An Apply Rule button appears in the too

  3. Click Apply Rule. The Apply Rule confirmation window with the following information, app

    1. It lists the instances which will be potentially affected by the rule.

    2. It offers the choice of what to do with those affected instances which cannot be placed according to the #. To stop them, or #. Leave them where they are (without stopping

  4. Select what to do with these instances which cannot be placed according to the rule and click OK. A message confirming the application of the placement rule will pop-up in the upper right-hand  corner of the screen.

Removing a VM Placement Rule

  1. Go to the Compute > Rules > view. The list of placement rules is displayed.

    Note

    ‘Admin’ users can view the list which includes all of the rules in the cluster. ‘Member’, ‘Tenant Admin’ or Read Only Admin users can view only those rules associated with the currently displayed projects listed.

  2. Highlight the row of the placement rule to remove. A Remove button appears in the toolbar.

  3. Click Remove. The Remove Rule confirmation window appers.

  4. Click OK. A message confirming the removal of the placement rule will pop-up in the upper right-hand  corner of the screen.