XCOMM0741I NEGOTIATING COMPRESSION METHOD FROM COMPRESS=LZSMALL TO COMPRESS=YES

Products

• XCOM Data Transport
• XCOM Data Transport - Windows
• XCOM Data Transport - Linux PC
• XCOM Data Transport - z/OS

Issue/Introduction

When sending from z/OS to a UNIX box, compression is being negotiated down to COMPRESS=YES for no apparent reason. Why is that?

Environment

Release: XCOM..002JP-12.0-XCOM Data Transport-for z/OS
Component:

Resolution

This happens because when you use the LZ (LSMALL, LZMEDIUM, LZLARGE, LZRW3) and Huffman compression routines you need to specify MAXPACK=31744 , PACK=LENGTH and RECSEP=NO. Setting RECSEP=NO and PACK=LENGTH will turn on large packing.

These compression routines must use a buffer with at least 500 bytes in order to be efficient. If XCOM detects that PACK=LENGTH is not specified and the value of MAXPACK= is not set to 31744 , it will negotiate compression down to COMPRESS=YES. RECSEP=YES must be specified with PACK=LENGTH or you will get the error message XCOMU0448E Type of Record Packing not Supported and the transfer will end with an error.

You can set the value of MAXPACK= in the config member or XCOMDFLT table or in a destination member for that partner receiving the transfer.

 

 

Additional Information

Please refer to the CA XCOM Data Transport for z/OS 12.0 Online documentation for details on the parameters.