DDR records are recorded on the logrec data set for each operator-initiated or system-initiated swap between direct access storage and magnetic tape devices and for each operator-initiated swap on a unit record device. The system requests DDR after a permanent (uncorrectable) I/O error has occurred. The operator can request DDR at any time by entering the SWAP command.
| Offset | Size (bytes) alignment (bits) | Field name | Description | |
|---|---|---|---|---|
| Dec | Hex | |||
| 0 | (0) | 1 | LRBHTYPE | Record key: |
| .11. .... | DDR record; type=X'60'. | |||
| 1 | (1) | 1 | LRBHSYS | System/Release level: |
| 100. .... | OS/VS2. | |||
| bits 3-7 | ||||
| 0-1F | Release level 0-31. | |||
| 2 | (2) | 1 | LRBHSWO | Record-independent switches: |
| 1... .... | More records follow. | |||
| 0... .... | Last record. | |||
| .1.. .... | Time-of-day (TOD) clock instruction issued. Used in conjunction with date and time values at displacements 8 and 12. | |||
| ..1. .... | Record truncated. (Not used for DDR record.) | |||
| ...1 .... | Record created by MVS/SP Version 2, 3, or 4. | |||
| .... 1... | TIME macro used. | |||
| .... .xxx | Reserved. | |||
| 3 | (3) | 3 | LRBHSW1 | Record-dependent switches: |
| Byte 0 | ||||
| 1... .... | Primary storage reconfiguration. | |||
| .1.. .... | Secondary storage reconfiguration. | |||
| ..1. .... | Operator requested reconfiguration. | |||
| ...1 .... | Permanent error caused reconfiguration. | |||
| .... xxxx | Reserved. | |||
| Bytes 1 and 2 | Reserved. | |||
| 6 | (6) | 1 | LRBHCNT | Record count: |
| bits 0-3 | Sequence number of this physical record. | |||
| bits 4-7 | Total number of physical records in this logical record. | |||
| 7 | (7) | 1 | Reserved. | |
| 8 | (8) | 4 | LRBHDATE | System date of incident. |
| 12 | (C) | 4 | LRBHTIME | System time of incident. |
| 16 | (10) | 1 | LRBHCPID | Machine version code. |
| 17 | (11) | 3 | LRBHCSER | Central processor serial number. |
| 20 | (14) | 2 | LRBHMDL | Central processor machine model number. |
| 22 | (16) | 2 | LRBHMCEL | Reserved. |
| END OF STANDARD HEADER | ||||
| 24 | (18) | 8 | LRBRJOB | Name of job using ‘FROM’ device. Field valid only if system initiated swap for permanent error or for operator initiated tape swaps. |
| 32 | (20) | 6 | LRBRVOL1 | VOLSER of volume mounted on ‘FROM’ swap device. |
| 38 | (26) | 6 | LRBRVOL2 | VOLSER of volume mounted on ‘TO’ swap devices. Field is zero if no volume is mounted on ‘TO’ device. |
| 44 | (2C) | 1 | LRBRPH1 | Physical ID of ‘FROM’ device (not the address). DASD only. |
| 45 | (2D) | 3 | LRBRCUA1 | Device number of ‘FROM’ device. |
| 48 | (30) | 4 | LRBRDEV1 | Device type of ‘FROM’ device. |
| 52 | (34) | 1 | LRBRPH2 | Physical ID of ‘TO’ device. DASD only. |
| 53 | (35) | 3 | LRBRCUA2 | Device number of ‘TO’ device. |
| 56 | (38) | 4 | LRBRDEV2 | Device type of ‘TO’ device. |