Bandwidth utilization in a PPRC system

A peer-to-peer remote copy storage system, comprising:

• a primary storage controller;
• a secondary storage controller;
• a plurality of links coupling the primary storage controller with the secondary storage controller;
• a plurality of substantially equal-size tracks collectively comprising a block of data to be transferred from the primary storage controller to the secondary storage controller;
• a plurality of data mover task control blocks (TCBs);
• a master TCB operable to supervise the transfer of the plurality of tracks;
• means for associating a first track of the block of data with a corresponding first data mover TCB of the plurality of data mover TCBs;
• means for transferring the first track to the secondary storage controller;
• the means associating the first track with the first data mover TCB including means for associating a second track of the block of data with a corresponding second data mover TCB of the plurality of data mover TCBs;
• the means for transferring the first track including means for transferring the second track to the secondary controller in a piped fashion relative to the transfer of the first track;
• the means for associating the first track with the first data mover TCB including means for continuing to associate tracks of the block of data to corresponding data mover TCBs of the plurality of data mover TCBs;
• means for monitoring the usage of the data mover TCBs;
• and
• if an insufficient number of data mover TCBs are available to be associated with the remaining tracks of the block of data:
• means for directing that the master TCB operate as a data mover TCB;
• and
• means for transferring the remaining tracks of the block of data to the secondary controller serially in a non-piped fashion.

A peer-to-peer remote copy primary storage controller coupled to a secondary storage controller through a plurality of links, the primary storage controller comprising:

• a plurality of substantially equal-size tracks collectively comprising a block of data to be transferred from the primary storage controller to the secondary storage controller;
• a plurality of data mover task control blocks (TCBs);
• a master TCB operable to supervise the transfer of the plurality of tracks;
• means for associating a first track of the block of data with a corresponding first data mover TCB of the plurality of data mover TCBs;
• means for transferring the first track to the secondary storage controller;
• the means associating the first track with the first data mover TCB including means for associating a second track of the block of data with a corresponding second data mover TCB of the plurality of data mover TCBS;
• the means for transferring the first track including means for transferring the second track to the secondary controller in a piped fashion relative to the transfer of the first track;
• the means for associating the first track with the first data mover TCB including means for continuing to associate tracks of the block of data to corresponding data mover TCBs of the plurality of data mover TCBs;
• means for monitoring the usage of the data mover TCBs;
• and
• if an insufficient number of data mover TCBs are available to be associated with the remaining tracks of the block of data:
• means for directing that the master TCB operate as a data mover TCB;
• and
• means for transferring the remaining tracks of the block of data to the secondary controller serially in a non-piped fashion.

A computer program product of a computer readable medium usable with a programmable computer, the computer program product having computer-readable code embodied therein for transferring data from a primary PPRC storage controller to a secondary storage controller over any of a plurality of links, the computer-readable code comprising instructions for:

• dividing a block of data into a plurality of substantially equal-size tracks;
• receiving a command to transfer the block of data from the primary storage controller to a secondary storage controller;
• allocating memory space in the primary storage controller to a master task control block (TCB) to supervise the transfer of the block of data;
• allocating memory space in the primary storage controller to a plurality of data mover TCBs;
• placing the plurality of data mover TCBs in a queue associated with the master TCB;
• associating a first track of the block of data with a corresponding first data mover TCB of the plurality of data mover TCBs;
• transferring the first track to the secondary storage controller;
• associating a second track of the block of data with a corresponding second data mover TCB of the plurality of data mover TCBs;
• transferring the second track to the secondary controller in a piped fashion relative to the transfer of the first track;
• continuing to associate tracks of the block of data to corresponding data mover TCBs of the plurality of data mover TCBs;
• monitoring the usage of the data mover TCBs;
• and
• if an insufficient number of data mover TCBs are available to be associated with the remaining tracks of the block of data:
• directing that the master TCB operate as a data mover TCB;
• and
• transferring the remaining tracks of the block of data to the secondary controller serially in a non-piped fashion.