Presentation of a read-only clone LUN to a host device as a snapshot of a parent LUN

1. A method comprising:

generating a read-write clone Logical Unit Number (LUN) of a parent LUN;

coalescing an identical data instance of the read-write clone LUN and the parent LUN in a data block of a volume of a storage system;

modifying a data structure at a block transfer protocol layer level to refer to the read-write clone LUN as a read-only clone LUN;

presenting the read-only clone LUN to a host device as a snapshot of the parent LUN;

and

coalescing the identical data instance of the read-write clone LUN and the parent LUN with a data deduplication operation; wherein the data deduplication operation is a Single Instance Storage (SIS) operation in which unique data blocks of the parent LUN and the read-write clone LUN are stored in the volume of the storage system and a meta-data is created that references the unique data blocks.

2. The method of claim 1 , further comprising:

modifying a Small Computer System Interface (SCSI) target to refer to the read-write clone LUN as read-only through a target module of the storage system.

3. The method of claim 2 , further comprising:

differentiating the read-write clone LUN from the parent LUN with a SCSI inquiry data.

4. The method of claim 1 , wherein coalescing the identical data instance of the read-write clone LUN and the parent LUN in the data block of the storage volume comprises:

implementing a block sharing operation between the read-write clone LUN and the parent LUN with a deduplication module.

5. The method of claim 1 , further comprising:

revising the data block transfer protocol layer to render the read-only clone LUN for presentation to the host device as the snapshot of the parent LUN.

6. The method of claim 1 , wherein a machine is caused to perform the method of claim 1 when a set of instructions in a form of a non-transitory machine-readable medium is executed by the machine.

7. A method, comprising:

generating a read-write clone Logical Unit Number (LUN) of a parent LUN;

coalescing an identical data instance of the read-write clone LUN and the parent LUN in a data block of a volume of a storage system;

modifying a data structure at a block transfer protocol layer level to refer to the read-write clone LUN as a read-only clone LUN;

presenting the read-only clone LUN to a host device as a snapshot of the parent LUN;

coalescing the identical data instance of the read-write clone LUN and the parent LUN with a data deduplication operation; and

preventing a modification of the read-only clone LUN through a command communicated from the host device to the storage system that refers to the read-only clone LUN as the snapshot to prevent a modification of the read-only clone LUN.

8. The method claim 7 , wherein the data deduplication operation is a Single Instance Storage (SIS) operation in which unique data blocks of the parent LUN and the read-write clone LUN are stored in the volume of the storage system and a meta-data is created that references the unique data blocks.

9. The method of claim 7 , further comprising:

revising the data block transfer protocol layer to render the read-only clone LUN for presentation to the host device as the snapshot of the parent LUN.

10. A method, comprising:

generating a read-write clone Logical Unit Number (LUN) of a parent LUN;

coalescing an identical data instance of the read-write clone LUN and the parent LUN in a data block of a volume of a storage system;

modifying a data structure at a block transfer protocol layer level to refer to the read-write clone LUN as a read-only clone LUN; and

presenting the read-only clone LUN to a host device as a snapshot of the parent LLTN;

wherein the coalescing occurs at most a 4 kilobyte granularity level, and operates on an active file system of the volume of the storage system, and

wherein the coalescing is a background process that is configurable to operate in a manner that is at least one of an automatic coalescing, a scheduled coalescing, and a manual coalescing through a Command Line Interface (CLI).

11. The method of claim 10 , further comprising:

coalescing the identical data instance of the read-write clone LUN and the parent LUN with a data deduplication operation; wherein the data deduplication operation is a Single Instance Storage (SIS) operation in which unique data blocks of the parent LUN and the read-write clone LUN are stored in the volume of the storage system and a meta-data is created that references the unique data blocks.

12. The method of claim 10 , further comprising:

revising the data block transfer protocol layer to render the read-only clone LUN for presentation to the host device as the snapshot of the parent LUN.

13. A system comprising:

a host device having an initiator that requests a snapshot of a parent Logical Unit Number (LUN);

a network;

a storage system coupled to the host device through the network to present a read-only clone LUN of the parent LUN to the host device as the snapshot of the parent LUN; and

a deduplication module of the storage system to coalesce an identical data instance of the read-write clone LUN and the parent LUN with a data deduplication operation; wherein the data deduplication operation is a Single Instance, Storage (SIS) operatio in which unique data blocks of the parent LUN and the read-write clone LUN are stored in the volume of the storage system and a meta-data is created that references the unique data blocks.

14. The system of claim 13 , further comprising:

a target module of the storage system to modify a small computer system interface (SCSI) target to refer to the read-write clone LUN as read-only clone LUN.

15. The system of claim 13 , wherein the read-write clone LUN is differentiated from the parent LUN with a SCSI inquiry data.

16. The system of claim 13 , wherein the storage system implements a block sharing operation between the read-write clone LUN and the parent LUN with the deduplication module.

17. A system of claim 13 , wherein a modification of the read-only clone LUN is prevented through a command communicated from the host device to the storage system that refers to the read-only clone LUN as the snapshot to prevent a modification of the read-only clone LUN.

18. The system of claim 13 , wherein a block transfer protocol layer is revised to render the read-only clone LUN for presentation to the host device as the snapshot of the parent LUN.

19. The system of claim 13 , wherein the coalescing occurs at most a 4 kilobyte granularity level, and operates on an active file system of the volume of the storage system, and wherein the coalescing is a background process that is configurable to operate in a manner that is at least one an automatic coalescing, a scheduled coalescing, and a manual coalescing through a Command Line Interface (CLI).