Use of predefined block pointers to reduce duplicate storage of certain data in a storage subsystem of a storage server

A method in a computing system for specially allocating data within the computing system, the method comprising:

• receiving, by an allocation component executing on a processor of the computing system, a request from a client to write a set of data blocks in a non-volatile mass storage facility of the computing system, the set of data blocks including a data block that includes data previously designated as special data, wherein the special data is pre-allocated in the non-volatile mass storage facility;
• for each data block in the set of data blocks, comparing, by the allocation component executing on the processor of the computing system, the data block to the special data,
• when the data block is determined to match the special data, assigning a special block pointer to the data block, the special block pointer pointing to a block address in the non-volatile mass storage facility, the special block pointer indicating that the corresponding data block was pre-allocated in both the non-volatile mass storage facility and a volatile memory of the computing system;
• and
• preventing the data block from being written to the non-volatile mass storage facility as a result of the received request.

A storage system comprising:

• a processor;
• a network communication interface to provide the storage system with data communication with at least one client over a network;
• a storage interface to provide the storage system with data communication with one or more mass storage devices, wherein the one or more mass storage devices includes a pre-allocated data block of special data;
• and
• a memory including contents of the pre-allocated data block and special allocation code that, when executed by the processor, causes the storage system to execute a special allocation process in response to a request received from the at least one client to read a portion of data from the one or more mass storage devices, the portion of data having a block pointer identifying a location of the one or more mass storage devices on which the portion of data is stored;
• comparing the block pointer to the special block pointer to determine whether the portion of data matches the contents of the pre-allocated data block;
• and
• when the block pointer matches the special block pointer, reading the contents of the pre-allocated data block from the memory of the storage system without issuing a request to read the contents of the pre-allocated data block from the one or more mass storage devices.

A non-transitory computer-readable storage medium for specially allocating data within a computing system, the storage medium comprising:

• instructions for receiving a request from a client to write a set of data blocks in a non-volatile mass storage facility of the computing system, the set of data blocks including a data block that includes data previously designated as special data, wherein the special data is pre-allocated in the non-volatile mass storage facility;
• instruction for comparing the data block to the special data for each data block in the set of data blocks;
• instruction for, when the data block is determined to match the special data, assigning a special block pointer to the data block, the special block pointer pointing to a block address in the non-volatile mass storage facility, the special block pointer indicating that the corresponding data block was pre-allocated in both the non-volatile mass storage facility and a volatile memory of the computing system;
• instruction for preventing the data block from being written to the non-volatile mass storage facility as a result of the received request.