Simulating an ILM policy

You should simulate a proposed policy on test objects before activating the policy and applying it to your production data. The simulation window provides a standalone environment that is safe for testing policies before they are activated and applied to data in the production environment.

Before you begin

About this task

You must carefully select the objects you want the proposed policy to test. To simulate a policy thoroughly, you should test at least one object for each filter in each rule.

For example, if a policy includes one rule to match objects in bucket A and another rule to match objects in bucket B, you must select at least one object from bucket A and one object from bucket B to test the policy thoroughly. If the policy includes a default rule to place all other objects, you must test at least one object from another bucket.

When simulating a policy, the following considerations apply:
  • After you make changes to a policy, save the proposed policy. Then, simulate the behavior of the saved proposed policy.
  • When you simulate a policy, the ILM rules in the policy filter the test objects, so you can see which rule was applied to each object. However, no object copies are made and no objects are placed. Running a simulation does not modify your data, rules, or the policy in any way.
  • The Simulation page retains the objects you tested until you close, navigate away from, or refresh the ILM Policies page.
  • Simulation returns the name of the matched rule. To determine which storage pool or Erasure Coding profile is in effect, you can view the Retention Diagram by clicking the rule name or the more details icon more details icon.
  • If S3 Versioning is enabled, the policy is only simulated against the current version of the object.


  1. Select and arrange the rules, and save the proposed policy.
    The Demo policy in this example has three rules:
    • The first rule, X-men, applies only to objects in a specific tenant account and uses an advanced filter to match series=x-men user metadata.
    • The second rule, PNGs, matches keys ending in .png.
    • The last rule is the stock rule, Make 2 Copies, and it is selected as the default. This rule applies to any objects that do not match the other rules.

    Viewing Proposed Policy page

  2. Click Simulate.
    The Simulation ILM Policy dialog box appears.
  3. In the Object field, enter the S3 bucket/object-key or the Swift container/object-name for a test object, and click Simulate.
    Note: A message appears if you specify an object that has not been ingested.

    Message if you specify missing object

  4. Under Simulation Results, confirm that each object was matched by the correct rule.
    In the example, the Havok.png and Warpath.jpg objects were correctly matched by the X-men rule. The Fullsteam.png object, which does not include series=x-men user metadata, was not matched by the X-men rule but was correctly matched by the PNGs rule. None of the test objects was matched by the Make 2 Copies rule

    Simulation results