Understanding the Difference Between “Preserve” and “Exclude” Data in ServiceNow Cloning
- davidyang88
- May 12
- 3 min read
Updated: May 13
Cloning is a vital feature in ServiceNow that allows administrators to replicate data from one instance to another. It is particularly useful for keeping development, test, and training environments aligned with production. However, to ensure cloning does not overwrite critical or environment-specific configurations, ServiceNow offers the ability to “Preserve” or “Exclude” data. Understanding the difference between these two options is essential for any ServiceNow administrator looking to manage data safely and effectively during a clone operation.
This article breaks down the concepts of "Preserve" and "Exclude" in ServiceNow cloning, clarifies common misunderstandings, and offers practical guidance with examples to support accurate configuration during your next cloning activity.
What Is Data Cloning in ServiceNow?
ServiceNow cloning refers to the process of copying data from a source instance (usually production) to a target instance (like development or testing). While this ensures consistency, not all data should be copied over, as some information must remain unique to the target environment. This is where the Preserve and Exclude options come into play.
Preserve Data: Retain and Restore
Definition:The "Preserve" option ensures that specified data on the target instance is saved before cloning starts and restored once the clone completes. This is especially important for environment-specific data such as integrations, authentication configurations, or other unique system settings.
When to Use:Preserve data when the target instance has configurations or records that must not be overwritten by the source instance.
Common Use Cases:
MID Server configurations (ecc_agent table)
LDAP connections
SSO settings
Outbound Email properties
How It Works:
Data in specified tables on the target instance is exported before the clone.
The clone operation proceeds, overwriting other tables with source instance data.
After cloning, the preserved data is re-imported, restoring the table's previous state.
Example:If the target environment has a functioning MID Server and you preserve the ecc_agent table, the MID Server settings will remain untouched after the clone is complete.
Exclude Data: Prevent Overwrite
Definition:The "Exclude" option instructs the cloning process to completely skip specified tables, meaning no data from the source instance is copied into the target for those tables.
When to Use:Exclude data when the target environment should neither receive new data from the source nor retain its own data in specific tables.
Common Use Cases:
Audit logs
Temporary work tables
Large transaction tables irrelevant to testing
Custom tables not required in non-production instances
How It Works:
The clone process ignores the excluded tables.
The resulting tables on the target instance are left empty (unless preserved separately).
Example:If the sys_audit table is excluded, the target instance will not receive audit records from the source, and any existing audit data will also be cleared unless preserved.
Combine Both for Control
You can combine Preserve and Exclude settings for fine-tuned control.
If a table is marked as Preserve only, its data will be backed up and restored after the clone.
If a table is marked as Exclude only, it will be ignored during the clone and emptied.
If a table is marked as both Preserve and Exclude, the data on the target will be untouched — the clone skips this table entirely, keeping the existing records intact.
Visual Summary:
Configuration | Behavior |
Preserve Only | Saves and restores data after clone |
Exclude Only | Leaves table empty post-clone |
Preserve + Exclude | Leaves table data on target untouched |
Conclusion
Understanding the distinction between “Preserve” and “Exclude” is critical for managing ServiceNow clone operations effectively. These settings provide fine-grained control over which data remains unchanged, which gets overwritten, and which is ignored completely.
Key Takeaways:
Use Preserve to safeguard environment-specific settings or configurations.
Use Exclude to prevent unnecessary or large tables from being cloned.
When used together, Preserve and Exclude ensure the table remains exactly as it was before cloning.
