Question: A Microsoft Exchange environment has 12,000 users, of which 8,000 are considered typical users who require 75MB of mailbox space, and 4,000 are considered heavy users who require 150MB of mailbox space. On the basis of the current environment, each user generates 0.7 IOPS. The measured read/write ratio in the environment is close to 2:1. User concurrency during the peak period is 90 percent. For Exchange 4- KB random writes, the benchmark from vendors specifies that 10-K drives are capable of 130 IOPS and 15- K drives are capable of 180 IOPS.
a. Provide the IOPS calculation for RAID 1+0 and RAID 5 configurations.
b. Compute the number of disks required with 10-K and 15-K rpm drives.
c. Validate whether the capacity will match the mailbox size requirements.