What Is Staggered Spin-Up?

The best way to start a conversation about staggered spin-up is to talk about the problem it solve. Staggered spin-up is a physical performance strategy for serial ATA hard disk drives or RAID DISK drive systems. With staggered spin-up, engineers handle the electrical load and system capacity during startup by staggering the times when disk drives begin input/output (I/O) operations. Imagine you're at the airport during rush hour and trying to get on your flight. You approach the gate agent with your ticket and are told that they've already started loading passengers onto their flight and that they'll be boarding soon but not right now. Suddenly, you realize why: they're staggered! They know that if they all try to board at once, it will cause delays in getting everyone on board. So instead, they shake boarding: first is group A; then group B; then group C; then group D; and finally group E. That's what staggered spinning up does: it groups together disks based on their power requirements so that when one set has completed its initialization sequence, another location can start its initialization sequence without having to wait for all available power supplies to become available before beginning operation. In data centers or clouds where the power supply is the limiting factor, staggered spin-up can significantly reduce the power consumption at peak load. In data centers or clouds where the cooling system is the limiting factor, staggered spin-up can reduce the drives' temperature, extending the hard drives' life. With the traditional strategy, all drives spin up when the device or system power is turned on but staggered spin-up delays the spin-up of some industries to provide a more stable demand to the power supply. This way, your hard drives can take advantage of a power supply's peak efficiency and help you avoid unnecessary wear and tear.