Explanation
The device defined by the UCB is currently in use
by the system data mover function.
System action
XRC or concurrent copy function is active.
System programmer response
The device is active as a primary
volume or a secondary volume in an XRC session. To reconfigure the
volume for an XRC session:
- Issue an XDELPAIR command for the volume (or for the corresponding
primary volume if this is a secondary volume) to remove the device
from the session.
- Complete the reconfiguration.
- Issue the XADDPAIR command, with the default copy option, to return
the volume pair to XRC control.
Source
Extended remote copy (XRC).