z/VSE Disk Layouts (DOSRES, SYSWK1)

The figures in this appendix show the space that is reserved on DOSRES and SYSWK1 for z/VSE.

Notes:
  1. The UNUSED SPACE and END.VTOC may be different, depending on the DASD model you use. For information on the exact disk capacity of your DASD model, refer to the hardware description of your respective DASD model.
  2. You are recommended to place the VTOC in the middle of the disk device.
  3. MCAT means that this space belongs to the VSE/VSAM master catalog, UCAT that it belongs to the VSE/VSAM user catalog.

Layout Depending on Environment Selected

In the following tables, the space reserved for holding the page data sets is open ended. To avoid overlaps, especially with the page data sets, you should not put any files in the reserved space area.

If you select predefined environment B during initial installation, an enlarged page data set of 512 MB (compared to 256 MB for predefined environment A) is active. The UNUSED SPACE area will thus be reduced by 256 MB.

If you select predefined environment C during initial installation, an enlarged page data set of 1792 MB (compared to 256 MB for predefined environment A) is active. The UNUSED SPACE area will thus be reduced by 1792 MB.

The minimum number of cylinders or blocks (as rounded values) for the three environments and for 3390 and FBA disks, are:
Table 1. Minimum Cylinders/Blocks Required, per Disk Type, for Environments A, B, C
3390 DOSRES (Minimum Cylinders) SYSWK1 (Minimum Cylinders)
Environment A 763 1,112
Environment B 1,127 2,212
Environment C 3,314 3,212
     
FBA DOSRES (Minimum Blocks) SYSWK1 (Minimum Blocks)
Environment A 879,232 1,507,380
Environment B 1,443,072 2,280,500
Environment C 4,510,720 ² 3,687,476
Notes:
  1. If you wish to use a page data set, you cannot install your z/VSE system with environment C on a z/VM virtual FBA, or z/VM emulated FBA. Both of these types of disk are limited to a size of 2 GB.
  2. If you use system journals for CICS®, refer to the layout below.