System and method for mapping file block numbers to logical block addresses
View Patent ↗A system and method for mapping file block numbers (FBNs) to logical block addresses (LBAs) is provided. The system and method performs the mapping of FBNs to LBAs in a file system layer of a storage operating system, thereby enabling the use of clients in a storage environment that have not been modified to incorporate mapping tables. As a result, a client may send data access requests to the storage system utilizing FBNs and have the storage system perform the appropriate mapping to LBAs.
1. A method for translating a file based data access request to a computer storage system, comprising:
receiving at a network interface the file based data read request from a client, the network interface attached to a wide area computer network (WAN);
writing the file based data read request to a virtual disk which appears to the client as a file based storage device;
writing the file based data read request from the virtual disk to a block based file system of the storage system;
maintaining a mapping of the file block numbers to a set of logical block addresses of a storage medium by the computer data storage system, the maintaining done with the client not having knowledge of a layout of the storage medium;
mapping the file based data read request into block based block access addresses in response to the mapping of the file block numbers to a set of logical block addresses of the storage medium;
accessing data requested by the file based data read request from block based storage devices in response to the block access numbers;
transferring the data requested to the network interface, and sending the data to the client over the WAN.
2. The method of claim 1 wherein a file block number comprises a sequentially increasing value identifying a specific location within a file.
3. The method of claim 1 wherein a logical block address further comprises a value identifying a particular block stored on a storage device associated with the storage system.
4. The method of claim 3 wherein the storage device further comprises a set of disks.
5. The method of claim 1 wherein the step of mapping the file block numbers to a set of logical block addresses is performed by a storage operating system executing on the storage system.
6. The method of claim 1 wherein the step of mapping the file block numbers to a set of associated logical block addresses is performed by a mapping function within a file system executing on a storage operating system of the storage system.
7. The method of claim 1 wherein the step of mapping utilizes a mapping table.