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Advanced Topics › z/VM Considerations › How You Determine Whether z/VM Is Sending Reserve CCWs to Devices

How You Determine Whether z/VM Is Sending Reserve CCWs to Devices

To see if z/VM is removing or sending reserve CCWs to a DASD, issue a QUERY command. To see if z/VM is sending reserve CCWs to a certain device, specify the address of that device as a parameter on the QUERY command. For example, to see if z/VM is sending reserve CCWs to device 123, issue the following Class B command: 

Q 123

To see if z/VM is sending reserve CCWs to any devices, issue this command instead:

Q DASD

If SHARED or DED is specified to the right of the volume label in the resulting display, then z/VM is sending reserve CCWs to the device. Otherwise, z/VM is removing reserve CCWs, which means that integrity cannot be ensured among real processors.