Data and interface module features
This information describes the data and interface module options for the IBM XIV
Storage System.
For data and interface modules with 1 TB limited-capacity, the modules contain
2 TB DDMs, but the usable capacity is limited to 1 TB by using the short-stroking
method. By short stroking the DDM, only the outer sectors of the disk platters are
used to store data. Head repositioning delays are minimized, which results in
shorter access times and increased I/O performance.
Capacity on Demand (CoD) modules are modules that are physically installed in
the rack and fully functional but that are not 'activated' for use until more capacity
is needed. Additional capacity is activated by ordering a miscellaneous equipment
specification (MES) with the appropriate CoD activation feature. In reality,
installing the CoD activation feature allows for the use of an additional,
incremental portion of total system capacity that is proportional to the share of a
CoD module in the system. For example in a 15-module system, if three of the
modules are ordered as CoD (and not yet activated), this means that initially the
customer is only licensed to use 12/15 of the system usable capacity. By activating
the three CoD modules, the customer will then be licensed to fully utilize the
system usable capacity (or 15/15 of the capacity).
CoD activation features do not require physical installation. If you receive
notification to install this feature, only report the installation according to the
field-reporting guide for your respective geographical area.
Table 12. Feature codes for data modules
Feature description
Feature code
Model
281x-114
Model
281x-214
Model
281x-314
1 TB limited-capacity data modules 1123 2016
2 TB data modules 1126 2026
2 TB CoD data module 1146 2028
2 TB module CoD activation 1149 4020
2 TB self-encrypting module CoD
activation
4021
3 TB data modules 1136 2036
3 TB CoD data module 1148 2038
3 TB module CoD activation 1150 4030
3 TB self-encrypting module CoD
activation
4031
4 TB data modules 2042 5042
4 TB CoD data module 2044 5044
4 TB self-encrypting module CoD
activation
4041 6041
6 TB data modules 2062 5062
6 TB CoD data module 2064 5064
6 TB self-encrypting module CoD
activation
4061 6061
18 IBM XIV Gen3 281x-11x, 281x-21x, and 281x-314 Planning Guide