To estimate the number of tape cartridges needed per workday, the planning team determines the amount of data to be backed up per workday. The amount of OAM data being backed up per workday is 572.2 MB (10 000 objects per day x 60 000 bytes per object = 600 000 000 bytes, which equates to 585 938 KB, or 572.2 MB).
Assuming the tape cartridges are filled to 100% of their estimated capacity, Table 1 shows the number of tape cartridges of each type of recording format combination that would be needed daily.
| Media type | MB written to tape per workday | Cartridge capacity for user data | Number of tape cartridges used per workday |
|---|---|---|---|
| Cartridge System Tape (18-track format) | 572.2 | 200 MB | 2.86 |
| Cartridge System Tape (36-track format) | 572.2 | 400 MB | 1.43 |
| Enhanced Capacity Cartridge System Tape (36-track format) | 572.2 | 800 MB | .715 |
| IBM High Performance Cartridge Tape (128-track format) | 572.2 | 10 GB | .056 |
| IBM Extended High Performance Cartridge Tape (128-track format) | 572.2 | 20 GB | .028 |
| IBM High Performance Cartridge Tape (256-track format) | 572.2 | 20 GB | .028 |
| IBM Extended High Performance Cartridge Tape (256-track format) | 572.2 | 40 GB | .014 |
| IBM High Performance Cartridge Tape (384-track format) | 572.2 | 30 GB | .019 |
| IBM Extended High Performance Cartridge Tape (384-track format) | 572.2 | 60 GB | .009 |
| IBM Enterprise Tape Cartridge (EFMT1 recording technology) | 572.2 | 300 GB | .002 |
| IBM Enterprise Extended Tape Cartridge (EFMT2 or EEFMT2 recording technology) | 572.2 | 500 GB | .0011 |
| IBM Enterprise Extended Tape Cartridge (EFMT3 or EEFMT3 recording technology) | 572.2 | 1000 GB | .00056 |
| IBM Enterprise Advanced Tape Cartridge (EFMT4 or EEFMT4 recording technology) | 572.2 | 4000 GB | .00016 |