Chapter 12. Configuration with the command-line interface  419 12.4 DS8880 storage configuration for the CKD volumes  12.4.1 Creating the arrays 12.4.2 Creating the ranks and extent pools Example 12-58 CKD ranks with different extent sizes ID Group State datastate Array RAIDtype extpoolID extpoolnam stgtype exts usedexts keygrp marray extsize (cap) =========================================================================================================================== R4 0 Normal Normal A4 5 P2 Small ckd 187636 9904 - MA19 21cyl R5 0 Normal Normal A5 5 P2 Small ckd 219245 9919 - MA24 21cyl R9 0 Normal Normal A9 5 P0 CKD_ ckd 4113 2406 - MA6 1113cyl R10 0 Normal Normal A10 5 P0 CKD_ ckd 3520 2399 - MA3 1113cyl dscli>  lsrank -l ... Example 12-57 Rank and extent pool creation for CKD volumes dscli>  mkrank -array A0 -stgtype ckd CMUC00007I mkrank: Rank R0 successfully created. dscli>  lsrank ID Group State datastate Array RAIDtype extpoolID stgtype ============================================================== R0 - Unassigned Normal A0 6 - ckd dscli>  mkextpool -rankgrp 0 -stgtype ckd CKD_High_0 CMUC00000I mkextpool: Extent Pool P0 successfully created. dscli> chrank -extpool P0 R0 CMUC00008I chrank: Rank R0 successfully modified. dscli>  lsextpool Name ID stgtype rankgrp status availstor (2^30B) %allocated available reserved numvol  =========================================================================================== CKD_High_0 0 ckd 0 below 252 0 287 0 0 You do not need to create volume groups or host connects for CKD volumes. If I/O ports in  FICON mode exist, access to CKD volumes by FICON hosts is granted automatically,  following the specifications in the input/output definition file (IODF). Array creation for CKD volumes is the same as for FB volumes. For more information, see  12.3.2, “Creating the arrays” on page 401. When ranks and extent pools are created, you must specify  -stgtype ckd . Then you can  create the extent pool as shown in Example 12-57. This list contains the steps to configure CKD storage in the DS8880: When defining a rank, you can also specify the extent size. Starting with DS8880 R8.1  firmware, you can have ranks and extent pools with large 1113 cylinder CKD extents, or small  21 cylinder CKD extents. The extent unit is specified with the  -extsize  parameter of the  mkrank  command. The first rank added to an extent pool determines the extent size of the  extent pool. Example 12-58 shows ranks with different extent sizes. 1. Create the arrays. 2. Create the CKD ranks. 3. Create the CKD extent pools. 4. Create the LCUs. 5. Create the CKD volumes.