Hi, Mike,
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Originally, CMS on CP-67 and VM-370 supported only 800 byte physical records (block size) for CMS minidisks.
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CP-67 and VM/370 CP supported 4K pages on disk.
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With CP-67 and VM/370 CP, you have to manually "carve up" DASD devices into one or more "minidisks" defined to CP, in the CP DIRECTory.
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With VM/BSEPP and SEPP and above (VM/SP, VM/ESA etc.) we got the choice of CMS minidisks using the EDF Extended Disk Format with block sizes of 512, 1024, 2048 or 4096.? ?So, depending on average file sizes, you could "tune" your CMS minidisks to eliminate "internal fragmentation."
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DOS-360 -> DOS/VS -> DOS/VSE did support four types of "library" files (somewhat akin to PDS):? SSL (source statement library (for macros and source copy books), RL (relocatable library) for object decks for use with the linkage editor, PL (procedure library) for JCL PROCs, and CIL or CL (Core Image Library) for link-edited executable program modules.
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DOS-360 -> DOS/VS -> early DOS/VSE did not use VTOC space management; sys.admins had to keep track of it manually.
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With DOS/VS and above, VSAM provides its own "space management" for allocating and managing VSAM ESDS, KSDS and RRDS datasets within VSAM spaces that a sys. admin. has defined ("carved out") on DASD.
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Mark S. Waterbury
