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System Programmer Reference › Utilities › VMBMCOPY Utility › How to Prepare to Use VMBMCOPY › VMBU--Determine A-Disk Size and Number of Tapes

VMBU--Determine A-Disk Size and Number of Tapes

Before you copy a catalog, determine the following media requirements:

Obtain this information by analyzing the output of VMBMCOPY LISTCAT. For example, the following is the LISTCAT command and output for DUMPFILE 209:

vmbmcopy listcat 209

DMSACP723I C (11B0) R/O 
CA VM:Backup Media Copy Utility, Function Level 1

FILENAME FILETYPE FM FORMAT LRECL RECS BLOCKS    DATE       TIME
00000209 DUMPJOB  C1 F       4096    1      1  2011-10-YY  12:52:38
00002022 DETAIL   C1 F       4096    1      1  2011-10-YY  12:52:38
VW4804   FILE0001 C1 F       4096    1      1  2011-10-YY  12:52:38

DASD 11B0 DETACHED
Ready;

Follow these steps:

  1. Run the VMBMCOPY LISTCAT function.
  2. Determine the minimum size of the A-disk. The A-disk must have enough space to hold two copies of the largest catalog that you plan to copy. Add up the number of 4096-byte blocks that each of the listed old catalog data files uses.
  3. Determine the number of tapes that VMBMCOPY reads when it makes the copy. The number of tapes that are read in a given copy corresponds to the number of DETAIL files that are listed. The volsers of the listed tapes are the filenames of the listed FILE0001 files. These volsers include the copies that were made. Only one DETAIL file is created for all the copies.
  4. Estimate the number of tapes that VMBMCOPY requires to hold the copied data. Follow these steps:
    1. Multiply the number of DETAIL files by the maximum capacity of the old media.
    2. Divide that size by the capacity of the new media. The result is the number of DETAIL files that the copy creates.
    3. Multiply the number of DETAIL files by the number of copies you plan to make.

      You now have the total number of tapes that VMBMCOPY uses to copy the old media.