Patent ID: 9354979
Filing Date: 2016-05-31
CPC Classification: G06F

Claim Text:
1. A computer program product comprising a non-transitory computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a host computing device, causes the host computing device to: create a record in a write log in the host computing device for a write command to write data to a primary storage site and mark the record as uncommitted; maintain a copy of the data to be written by the write command in the record in the write log in the host computing device; issue the write command from the host computing device to a primary storage controller at a primary storage site; create a tracker command having a reference to the write command; issue the tracker command from the host computing device to the primary storage controller; exchange an association between the write command and the tracker command with the primary storage controller, wherein the primary storage controller creates a record in a local log at the primary storage site for the tracker command and wherein the primary storage controller returns an acknowledgement associated with the tracker command responsive to the data being replicated to the secondary storage site; responsive to receiving an acknowledgement from the primary storage controller that the data have been written to the primary storage site, mark the record as unreplicated; and responsive to receiving an acknowledgement from the primary storage controller that the data have been replicated to a secondary storage site, erase the record in the write log and delete the copy of data in the host computing device, wherein the primary storage controller erases the record in the local log responsive to the data being replicated to the secondary storage site.