Consistent replication across multiple storage devices

A computer readable storage medium that stores computer software that is executable by at least one processor and that concurrently replicates a plurality of storage devices, the computer software on the computer readable storage medium comprising:

• executable code that disables writes to all of the storage devices;
• executable code that, after disabling writes, sets a pending state change indicator for all of the storage devices without altering a replication state of any of the storage devices, the replication state of a particular storage device that varies according to whether the particular storage device has been replicated by a replication operation;
• and
• executable code that enables writes to the storage devices after setting the pending state change indicator.

A method of concurrently replicating a plurality of storage devices, comprising:

• setting a first indicator to be inactive, wherein the first indicator causes writes to be disabled to the storage devices when the first indicator is set to active;
• setting a second indicator to inactive, wherein the second indicator causes a change in a replication state for the plurality of storage devices when the second indicator is set to active, the replication state of a particular storage device varying according to whether the particular storage device has been replicated by a replication operation;
• setting a third indicator to inactive, wherein the third indicator causes writes to be enabled to the storage devices when the third indicator is set to active;
• following setting the first, second, and third indicators to inactive, setting the first indicator to active;
• following setting the first indicator to active, setting the second and third indicators to active;
• and
• following setting the second and third indicators to active, setting the first indicator to inactive.