Hi @jack33 ,
As per my Understanding problem Error Summary:
Discovery status is FAILURE
Identification sections in pattern failed:
java.lang.ClassCastException: class java.lang.String cannot be cast to class java.util.List
Root Cause:
The Identification section of the discovery pattern is expecting a List data type (e.g., an array or multiple values), but it’s receiving a String instead.
This typically happens when a field like serial_number, dns_domain, or any multi-instance identifier is misconfigured.
Where this Happens:
* Inside the Identification Section of the EMC Isilon Discovery Pattern (likely Storage Device - EMC Isilon).
* A step that is meant to return a List is returning a String, and this breaks identification logic.
Solution steps which might help you.
1. Open the Discovery Pattern
* Go to Discovery Patterns → Search for: Storage Device - EMC Isilon
* Open the pattern used for Isilon discovery.
2. Check the Identification Section
* Click on the Identification section inside the pattern.
* Look for any step or variable that is used as a List identifier (e.g., serial number, MAC address, IP address list).
3. Validate the Data Type
* Ensure that the values passed into the identification are of the expected List type.
Examples:
If using a script step like:
return probe.parm1; // BAD if this is a string
Fix it to:
return [probe.parm1]; // GOOD – converts to a List
Or, if dealing with multiple values:
return probe.parm1.split(','); // assuming comma-separated string
4. Check Previous Steps
* Review any step that gathers data before the identification.
* Make sure they're not passing single strings to identification fields that expect lists.
5. Test Pattern Execution
* After updating the pattern, re-run the discovery for EMC Isilon.
* Monitor the discovery log to confirm that the error is resolved.
Please appreciate the efforts of community contributors by marking appropriate response as Mark my Answer Helpful or Accept Solution this may help other community users to follow correct solution in future.
Thank You
AJ - TechTrek with AJ - ITOM Trainer
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ServiceNow Community MVP 2025
