Creating output data sets with correct attributes
When you specify particular attributes, you can use the DFSTRA01, DFSTRA02, and DFSTRA0T data sets to hold your trace data.
Create the DFSTRA01 and DFSTRA02 trace data sets with the following
attributes, in order for you to use them to hold your trace data:
- DSORG
- PS (Physical Sequential)
- RECFM
- VB
- LRECL
- 4016
- BLKSIZE
- A
formula of: (LRECL*N)+4. The block size must be a multiple of the
LRECL (4016), with the additional 4 bytes for the block descriptor
word.Recommendation: Use a BLKSIZE of 20,084, which is five logical records in length (4016 bytes, multiplied by 5), plus the block descriptor word (4 bytes). The BLKSIZE of 20,084 is recommended for current DASD because it is equal to one-half track.
Recommendation: Allocate
these data sets as a single extent, meaning contiguous tracks. Do
not specify secondary allocation.
In order to use a tape to hold the external trace data set, you
must use the DFSTRA0T data set. DFSTRA0T must be dynamically allocated
with the following attributes:
- DSORG
- PS (Physical Sequential)
- RECFM
- VB
- LRECL
- 4016
- BLKSIZE
- A formula of: (LRECL*N)+4. The block size must be a multiple of the LRECL (4016), with the additional 4 bytes for the block descriptor word.
In order to dynamically create these data sets, use the following
JCL example.
/STEP EXEC IMSDALOC
//SYSIN DD *
DFSMDA TYPE=INITIAL
DFSMDA TYPE=TRACE,DDNAME=DFSTRA01,DSNAME=IMS41.DFSTRA01
DFSMDA TYPE=TRACE,DDNAME=DFSTRA02,DSNAME=IMS41.DFSTRA02
DFSMDA TYPE=TRACE,DDNAME=DFSTRAT2,DSNAME=IMS41.DFSTRA0T
DFSMDA TYPE=FINAL
END