This article describes the difference in the way the request system snapshot command creates a snapshot in Junos OS and Junos OS Evolved, which would be important to know when devices are migrated from Junos OS to Junos OS Evolved.

In Junos OS, when the request system snapshot command is executed without any options, by default, it creates a snapshot for the Routing Engine on which the command was executed; that is, if the command was executed on re0, a snapshot will be created only on re0. 

In Junos OS Evolved, when the request system snapshot command is executed without any options, by default, it creates a snapshot for both Routing Engines. This behavior has been modified and from Junos OS 20.3R2-EVO onward, it matches the default behavior of Junos OS in creating a snapshot only for the local RE.