Modifying the migration queue limit value

The migration queue limit value can be modified to something other than the default of 50 000. This is recommended only if your installation is receiving too many unwanted ARC0535I messages.

To change the default value to a higher value, in this example 100 000 (X'186A0'), issue:

PATCH .MGCB.+100 X'00186A0' VERIFY(.MGCB.+100 X'0000C350')

To return to the default value of 50 000 (X'C350'), issue:

PATCH .MGCB.+100 X'0000C350' VERIFY(.MGCB.+100 X'00186A0')

Note:

Take care in increasing the migration queue limit to a value that is reasonable, based upon the number of data sets which reside on your volumes. Increasing the migration queue limit to a value that is too high may cause ABEND878s.
If you do intend on increasing the migration queue limit, then you should also consider decreasing the amount of migration tasks to avoid a drastic increase in the amount of virtual memory used.
The patch values are reset to the default after DFSMShsm is restarted. In order to modify it again, you will need to reissue the patch command, or else you can add the patch command to the ARCCMDxx parmlib member that DFSMShsm uses during startup.