Question $4.$ Assume a NetApp storage server has the following components and MTTF:

a$)10$ disks, each rated at $1,000,000-$hour MTTF

b$)$ SCSI controller, $500,000-$hour MTTF

c$)$ power supply, $200,000-$hour MTTF

d$)$ fan, $200,000-$hour MTTF

e$)$ SCSI cable, $1,000,000-$hour MTTF

The age of the component is important in failures; all the above failures are independent. Compute the MTTF of the system as a whole.