ICETOOL notes and restrictions

Small REGION values can cause storage problems when ICETOOL calls DFSORT. Large REGION values give DFSORT the flexibility to use the storage it needs for best performance. We recommend that you use a REGION value of at least 1024K for ICETOOL.
Each ICETOOL operation results in a set of ICETOOL messages in the TOOLMSG data set, and a corresponding set of DFSORT messages in the DFSMSG data set. For a particular call to DFSORT, you can relate the sets of messages in the TOOLMSG and DFSMSG data sets by using the unique identifier for that call. Just match the identifier printed in ICETOOL message ICE606I or ICE627I to the same identifier printed in DFSORT message ICE200I. This is particularly important if an ICETOOL operation fails due to an error detected by DFSORT (return code 16).
Because ICETOOL calls DFSORT, the installation defaults used for DFSORT are those in effect for the appropriate program-invoked environment, that is, the ICEAM2 or ICEAM4 defaults, or the ICETDx defaults activated for ICEAM2 or ICEAM4. The DFSORT installation defaults apply only to DFSORT, not to ICETOOL. For example, installation option MSGCON=ALL causes DFSORT, but not ICETOOL, to write messages to the master console. The one exception is the SDBMSG installation option; the value in effect from ICEAM2 or ICEAM4 is used for ICETOOL's TOOLMSG data set.
When ICETOOL calls DFSORT, it passes control statements and options appropriate to the specific operations being performed. You should not override the DFSORT control statements or options passed by ICETOOL unless you understand the ramifications of doing so.
For example, ICETOOL passes the NOABEND option to DFSORT to ensure that ICETOOL will regain control if DFSORT issues an error message. If you specify:
```
//DFSPARM DD *
  DEBUG ABEND
```
you cause DFSORT to abend when it issues an error message, thus preventing ICETOOL from performing subsequent operators.
Tape work data sets cannot be used with ICETOOL.
An ON field must not include bytes beyond the fixed part of variable length input records. The entire field specified must be present in every input record, otherwise, DFSORT issues message ICE015A, ICE218A, or ICE027A and terminates.