If you do not specify the space required for the dataset when it reaches the mainframe, then XCOM for z/OS will use the default specified in the config member or xcomdflt on the mainframe side. If this is not large enough, you will get the B37 abend.
You can resolve this problem by specifying the space parameters when submitting the transfer from Windows or ask the mainframe administrator to increase the default space settings on the mainframe
1) Sending from Windows
There are space parameters that you can specify on Windows to make sure there is enough room for the file on the mainframe. The z/OS administrator can assist you in determining what these values should be:
If you are submitting the transfer from the GUI,
- Under Remote System Identification and Parameter, For System Type, select z/OS and you will see all the needed parameters to specify the type and size of file on the mainframe.
If you are submitting the transfer from the command line, you can specify these individual parameters for the type and size of the file:
You need to review the values you have defined to create the data set on z/OS. All the parameters are defined in the manual.
2) From the mainframe side. Ask the z/OS administrator to increase the default space parameters in the config member or xcomdflt.