Warning: "Increasing burst size for interface <if-name> from <X> to smallest supported value of <Y> bytes"
Cause
You tried to configure a burst size for a QoS policy that is less than the interface's MTU size. To ensure correct operation, the system automatically adjusted the value that you tried to configure.
The burst size must be at least equal to the interface's MTU size. If the burst size is smaller than the interface's MTU, the system would not be able to send an MTU sized packet.
You will trigger this warning if you combine commands like these:
set policy qos name <policy-name> shaper burst <X>
set interfaces dataplane <interface-name> policy qos <policy-name>
set interface dataplane <interface-name> mtu <Y>Remedy
You don't need to do anything — the system adjusted the MTU size so that MTU sized packets can be sent. However, you may want to review your burst and MTU settings and modify them to remove this warning.