What will happen if the oil level in the tank is insufficient when the hydraulic pump is in operation?

What will happen if the oil level in the tank is insufficient when the hydraulic pump is in operation?

Main phenomena and reasons:
1. Noise (cavitation and bubble rupture)
Insufficient oil intake causes the pump to suck in air. Compressing and releasing bubbles produces a violent impact, producing an unusually harsh noise
2. Vibration (unstable operation)
The mixture of oil and gas leads to a decrease in volumetric efficiency. Pressure pulsation intensifies, causing significant vibration in the pipeline and pump body
3. Insufficient pressure and decreased efficiency
Air has high compressibility, making it difficult for the system to establish normal working pressure. The hydraulic cylinder or motor operates slowly or weakly