An attempt to issue I/O from the SDM host to the primary storage subsystem has timed out. The timeout value is stored in the user defined StorageControlTimeout value. This is for component 5695DF117 System Data Mover (SDM).
Typically, the presence of IOS messages indicate a networking issue. The I/O timeout is justified by the loss of connectivity from the SDM hosts to the primary storage subsystem. Check the SYSLOG for IOS messages. If present, users should follow up with their networking vendor. Once the network is stabilized, the user can resume the mirror.
FTP the following documentation to the IBM support center for further diagnostics: SYSLOG
Correct any connectivity issues in the hardware network.