System clone The system clone application allows users with the clone_admin or admin role to clone data from one instance to another. This functionality is primarily used to clone a production instance over an existing sub-production instance before developing or testing changes. All clones are performed using the most recent nightly backup. This application applies to instances in Gen2 and later datacenters. Figure 1. Clone process In response to a clone request, the ServiceNow platform performs the following tasks: Generates a file to preserve operational data on the target server.This file contains the data preserved by data preservers. Copies the database schema from the source instance to the target instance. Creates tables in the target instance database using the source instance table definitions. Copies data from the most recent nightly backup of the source instance to the target instance database.Certain large tables are normally excluded. These include audit, log, and email tables. Briefly disables UI traffic and requests to the target instance server. Displays the message Clone in progress... to any user accessing the target instance. Restores operational data preserved from the target instance. Runs any post-clone cleanup scripts on the target instance. Briefly suspends all email functions on the target instance. Queues an event to regenerate text indexes. Enables UI traffic and requests to the target instance server. During a clone, the target instance may be intermittently unavailable. After clone completion, you have up to 24 hours to contact ServiceNow Customer Support and request a rollback of the target instance to its pre-clone state. You are notified when the rollback is complete. Clone to an instance on a different version The System Clone application can target an instance running a different instance version from the source. A central web service controls clone processing and automatically modifies the target instance version to match the source instance version. This matching process starts up to 8 hours before the time specified in the Date and time field on the System Clone form. This web service also ensures that there is enough disk space on the target instance for the clone to proceed. When cloning from a backup, the target instance does not need additional time to upgrade or downgrade. The ServiceNow platform performs any version changes during a brief window where the target instance is unavailable, after it copies data from the source instance backup. Clone from a backup The platform uses data from the most recent nightly backup of the source instance when cloning. Backups used for cloning are at most 36 hours old. After cloning from a backup, the target instance is unavailable for several minutes before the clone is marked as complete in the source instance. If the source and target instances are on different versions of the ServiceNow platform, the target instance is modified to match the source instance version during this time. When starting a clone from a backup, the date and time the backup was taken, as well as periodic progress messages, appear in the Clone Log related list. Figure 2. System clone backup log Clone over production instances Production instances cannot be used as the target instance for a clone after the instance is live. Production clones are created during non-core business hours. Tables are backed up sequentially rather than simultaneously. Modifying data on the source instance during a clone can cause a data mismatch between records or duplicate record entries. This issue is minimized by running a clone after normal business hours. When scheduling a clone for a production instance, the system automatically follows this process: Determines the instance region. Determines the non-core business hours for the region. Restricts the possible cloning time that can be specified on the Clone Request form to the non-core hours. Region Non-core business hours Americas East Coast 23:00 to 04:00 Eastern time (UTC –5) and all day Saturdays and Sundays Americas West Coast 20:00 to 01:00 Pacific time (UTC –8) and all day Saturdays and Sundays Australia 23:00 to 04:00 Australian Eastern time (UTC +10) and all day Saturdays and Sundays Europe Amsterdam 00:00 to 05:00 Central European time (UTC +1) and all day Saturdays and Sundays Europe London 23:00 to 04:00 British time (UTC) and all day Saturdays and Sundays Asia Hong Kong 23:00 to 04:00 Hong Kong time (UTC +8) and all day Saturdays and Sundays Asia Singapore 23:00 to 04:00 Singapore standard time (UTC +8) and all day Saturdays and Sundays Set up system cloneYou can perform optional, pre-cloning tasks before you request a clone. For example, you can control the exclusion of certain tables from cloning and preserve data on the clone target instance.Data preservation on cloning target instancesYou can use data preservers to protect data on the target instance from being overwritten. If you have custom applications, you must also manually preserve unpublished application content.Use system cloneStart the cloning process by requesting the clone, and then perform any post-clone cleanup that might be necessary.