Method and system for synchronizing storage system data

A method for comparing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system, comprising:

• generating an initial value associated with the first unit of data;
• transmitting the initial value from the first storage system to the second storage system;
• generating a first digest that represents the second unit of data;
• deriving a first encoded value using the first digest and the initial value;
• transmitting the first encoded value from the second storage system to the first storage system;
• generating a second digest that represents the first unit of data;
• deriving a second encoded value using the second digest and the initial value;
• and
• determining whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value.

A method for synchronizing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system, comprising:

• generating an initial value associated with the first unit of data;
• transmitting the initial value from the first storage system to the second storage system;
• generating a first digest that represents the second unit of data;
• deriving a first encoded value using the first digest and the initial value;
• transmitting the first encoded value from the second storage system to the first storage system;
• generating a second digest that represents the first unit of data;
• deriving a second encoded value using the second digest and the initial value;
• determining whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value;
• and
• sending a copy of the first unit of data from the first storage system to the second storage system, and storing the copy in the second storage system, if the first unit of data is determined to be different from the second unit of data.

A method for backing up a first unit of data stored on a first storage system, comprising:

• generating an initial value associated with the first unit of data;
• transmitting the initial value from the first storage system to a second storage system;
• generating a first digest that represents a second unit of data stored on the second storage system;
• deriving a first encoded value using the first digest and the initial value;
• transmitting the first encoded value from the second storage system to the first storage system;
• generating a second digest that represents the first unit of data;
• deriving a second encoded value using the second digest and the initial value;
• determining whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value;
• and
• storing a copy of at least one of the first unit of data and the second unit of data, if the first unit of data is determined to be different from the second unit of data.

A system for comparing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system, comprising:

• a first controller for generating a first digest that represents the first unit of data, and for deriving a first encoded value using the first digest and a predetermined value;
• and
• a second controller for generating a second digest that represents the second unit of data, and for deriving a second encoded value using the second digest and the predetermined value;
• wherein the second controller determines whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value.

A system for comparing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system, comprising:

• a first controller for generating an initial value associated with the first unit of data;
• a first interface for transmitting the initial value from the first storage system to the second storage system;
• a second controller for generating a first digest that represents the second unit of data, and for deriving a first encoded value using the first digest and the initial value;
• and
• a second interface for transmitting the first encoded value from the second storage system to the first storage system;
• wherein, the first controller generates a second digest that represents the first unit of data, derives a second encoded value using the second digest and the initial value, and determines whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value.

A system for synchronizing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system, comprising:

• a first controller for generating an initial value associated with the first unit of data;
• a first interface for transmitting the initial value from the first storage system to the second storage system;
• a second controller for generating a first digest that represents the second unit of data, and for deriving a first encoded value using the first digest and the initial value;
• and
• a second interface for transmitting the first encoded value from the second storage system to the first storage system;
• wherein, the first controller generates a second digest that represents the first unit of data, derives a second encoded value using the second digest and the initial value, and determines whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value, and the first controller sends a copy of the first unit of data from the first storage system to the second storage system, the copy being stored in a memory in the second storage system, if the first unit of data is determined to be different from the second unit of data.

A system for backing up a first unit of data stored on a first storage system, comprising:

• a first controller for generating an initial value associated with the first unit of data;
• a first interface for transmitting the initial value from the first storage system to a second storage system;
• a second controller for generating a first digest that represents a second unit of data stored on the second storage system, and for deriving a first encoded value using the first digest and the initial value;
• and
• a second interface for transmitting the first encoded value from the second storage system to the first storage system;
• wherein, the first controller generates a second digest that represents the first unit of data, derives a second encoded value using the second digest and the initial value, and determines whether the first unit of data and the second unit of data are duplicates of one another by comparing the first encoded value and the second encoded value, a copy of at least one of the first unit of data and the second unit of data being stored in a memory, if the first unit of data is determined to be different from the second unit of data.