The effective storage capacities of IBM DASD devices vary, depending on how the devices are being used. The database manager uses VSE/VSAM for managing DASD space for the directory data set, the log, and the dbextents. The directory data set uses 512-byte control intervals while the log and dbextent data sets are managed with 4-kilobyte control intervals.
Table 37 and Table 38 show the capacities of IBM devices for
storing log and dbspace pages (dbextent space). Table 39 and Table 40 show the capacities for storing directory
information.
Table 37. Log and Dbextent Storage Capacities of IBM Count-Key-Data DASDs
| DASD Type | Number of Cylinders | Tracks for Each Cylinder | Megabytes for Each Cylinder | Megabytes for Each Volume |
|---|---|---|---|---|
| 3375 | 959 | 12 | 0.3749 | 359 |
| 3380 J | 885 | 15 | 0.5858 | 518 |
| 3380 E | 1,770 | 15 | 0.5858 | 1,036 |
| 3380 K | 2,655 | 15 | 0.5858 | 1,555 |
| 3390-1 | 1,113 | 15 | 0.7031 | 782 |
| 3390-2 | 2,226 | 15 | 0.7031 | 1,565 |
| 3390-3 | 3,339 | 15 | 0.7031 | 2,347 |
| 3390-9 | 10,017 | 15 | 0.7031 | 7,041 |
| 9345-1 | 1,440 | 15 | 0.5858 | 843 |
| 9345-2 | 2,156 | 15 | 0.5858 | 1,262 |
Table 38. Log and Dbextent Storage Capacities of IBM FBA DASDs
| DASD Type | Megabytes for Each Volume | 4 Kilobyte Pages for Each Volume |
|---|---|---|
| 3370-1 | 272.4 | 69,750 |
| 3370-2 | 348.0 | 89,094 |
| 9332-400 | 175.7 | 45,004 |
| 9332-600 | 270.8 | 69,350 |
| 9335 | 392.9 | 100,589 |
| 9336-010 | 449.2 | 115,014 |
| 9336-020 | 816.8 | 209,110 |
| 9336-025 | 816.8 | 209,110 |
| 0671 | 280.5 | 71,820 |
Table 39. Directory Storage Capacities of IBM Count-Key-Data DASDs
| DASD Type | Number of Cylinders per Volume | Tracks for Each Cylinder | Megabytes for Each Cylinder | Megabytes for Each Volume |
|---|---|---|---|---|
| 3375 | 959 | 12 | 0.2343 | 224 |
| 3380 J | 885 | 15 | 0.3295 | 291 |
| 3380 E | 1,770 | 15 | 0.3295 | 583 |
| 3380 K | 2,665 | 15 | 0.3295 | 874 |
| 3390-1 | 1,113 | 15 | 0.3645 | 405 |
| 3390-2 | 2,226 | 15 | 0.3645 | 811 |
| 3390-3 | 3,339 | 15 | 0.3645 | 1,217 |
| 3390-9 | 10,017 | 15 | 0.3645 | 3,651 |
| 9345-1 | 1,140 | 15 | 0.3002 | 432.28 |
| 9345-2 | 2,156 | 15 | 0.3002 | 647.23 |
Table 40. Directory Storage Capacities of IBM FBA DASDs
| DASD Type | Megabytes for Each Volume | 512-Byte Blocks for Each Volume |
|---|---|---|
| 3370-1 | 272.4 | 558,000 |
| 3370-2 | 348.8 | 712,752 |
| 9332-400 | 175.7 | 360,036 |
| 9332-600 | 270.8 | 554,800 |
| 9335 | 392.9 | 804,714 |
| 9336-010 | 449.1 | 920,115 |
| 9336-020 | 816.8 | 1,672,881 |
| 9336-025 | 816.8 | 1,672,881 |
| 0671 | 280.5 | 574,560 |
These capacity charts are referenced in later calculations for determining data set allocations of the directory, log, and dbextent data sets.
Table 41 shows the minimum space allocations for a log or dbextent data set.
Table 41. Minimum Space Allocations for Log and Dbextent Data Sets
| DASD Type | Minimum Space Allocation |
|---|---|
| 3375 | 1 cylinder |
| 3380 | 1 cylinder |
| 3390 | 1 cylinder |
| 9345 | 1 cylinder |
| FBA | 528 Blocks |