Determining the size of the CI

The choice of a CI size depends on several factors.

The factors include:

• CI sizes of 512, 1 KB, 2 KB, 4 KB, and up to 28 KB in 4 KB increments are supported.
• Only one RAP exists per CI. The average record length has to be considered. In the base section of the root addressable part, a CI can be shared only by the roots that randomize to its RAP and their DDEP segments.
• Track utilization according to the device type.
• SDEP segment writes. A larger CI requires a fewer number of I/Os to write the same amount of SDEP segments.
• The maximum segment size, which is 28,552 bytes if using a 28 KB CI size.