There are three good ways to create hole patterns on the outside of tubes or cylindrical parts.  Use one of these three depending on your needs.

Create a hole pattern using 3D Hole Wizard Sketch and Circular pattern

Create your initial pattern along the length of the tube. Start by selecting the Hole Wizard first, this puts it in the 3D sketch mode. In the type tab set the hole type and size. Next select the position tab and use some construction sketches to define the initial hole positions, place your hole points on the surface of the tube and fully define the points for the holes to the construction sketches and complete the feature.
In the example below I created a construction line vertical along Y from the center of the end face and another at 30 degrees. I then set two construction lines down the length of the tube coincident with the end construction lines and the opposite end face and set them along the Z axis.

Next, turn on the temporary axis for the cylindrical feature and use it for a Circular pattern, set the instance count and angle and select the previous hole feature to pattern it.
In the example below I set the circular pattern instance at 6 with equal spacing about 360 degrees.

Completed 3D Hole Wizard with circular pattern on Tube

In the example below the Hole pattern resulted in 24 equally space holes about the outside surface of the tube