Method and Apparatus for Tiered Storage

Abstract

A system for storing file data and directory data received over a network includes a network interface in communication with the network which receives NAS requests containing data to be written to files from the network. The system includes a first type of storage. The system includes a second type of storage different from the first type of storage. The system includes a policy specification n which specifies a first portion of one or more files' data which is less than all of the files' data is stored in the first type of storage and a second portion of the data which is less than all of the data of the files is stored in the second type of store. The system comprises a processing unit which executes the policy and causes the first portion to be stored in the first type of storage and a second portion to be stored in the second type of storage. A method for storing file data and directory data received over a network.

1 . A system for storing file data and directory data received over a network comprising:
 a network interface in communication with the network which receives NAS requests containing data to be written to files from the network;   a first type of storage;   a second type of storage different from the first type of storage;   a policy specification which specifies a first portion of one or more files' data which is less than all of the files' data is stored in the first type of storage and a second portion of the data which is less than all of the data of the files is stored in the second type of store; and   a processing unit which executes the policy and causes the first portion to be stored in the first type of storage and a second portion to be stored in the second type of storage.   
     
     
         2 . A system as described in  claim 1  where the policy specification is stored in a file within the first type of storage or the second type of storage. 
     
     
         3 . A system as described in  claim 1  including a management database outside of the first type of storage or the second type of storage where the policy specification is stored in the management database. 
     
     
         4 . The system as described in  claim 1  wherein the policy specification specifies the first portion and the second portion of one or more files' data, where either portion may include file system meta-data. 
     
     
         5 . The system as described in  claim 4  wherein the policy specification for the first portion or the second portion of one or more files' data includes meta-data containing block addressing information. 
     
     
         6 . The system as described in  claim 1  including a buffer module having buffers and which reads and writes data into the buffers. 
     
     
         7 . The system as described in  claim 6  including an inode attribute manager which updates attributes in an inode. 
     
     
         8 . The system as described in  claim 7  including a directory manager which treats a directory object as a set of mappings between file names and inode identifiers. 
     
     
         9 . The system as described in  claim 7  including a data manager which copies data to and from the buffers. 
     
     
         10 . The system as described in  claim 9  including an inode object allocator which allocates inodes and tags them with policy specifications. 
     
     
         11 . A system as described in  claim 10  including a NAS server operations module which receives incoming NAS requests and invokes local storage operations interfacing with the inode attribute manager, the directory manager, the data manager and the inode object allocator for reading and writing file and directory attributes, reading and writing file data, and performing directory operations. 
     
     
         12 . The system as described in  claim 10  including a NAS cache operations module which acts as a cache of data storage in one or external NFS servers and which creates and maintains cached versions of actively accessed directories and files stored at the external NFS server. 
     
     
         13 . A system as described in  claim 1  wherein at least two files are stored within a directory, where a Block Allocator allocates some blocks to a first file in the directory from a first type of storage, and allocates some blocks to a second file in the directory from a second type of storage different from the first type of storage. 
     
     
         14 . A system as described in  claim 13  including a Block Allocator that allocates blocks for a file from a first type of storage and additional blocks for the same file from a second type of storage different from the first type of storage. 
     
     
         15 . A system as described in  claim 14  where the Block Allocator determines the blocks to be allocated to a file from a first type of storage, and the blocks to be allocated from a second type of storage different from the first type of storage, based upon the policy associated with the file. 
     
     
         16 . A method for storing file data and directory data received over a network comprising the steps of:
 receiving NAS requests containing data to be written to files from the network at a network interface;   executing with a processing unit the policy specification which specifies a first portion of one or more files' data which is less than all of the files' data is stored in a first type of storage and a second portion of the data which is less than all of the data of the files stored in the second type of data which is different from the first type of storage; and   causing with the processing unit the first portion to be stored in the first type of storage and the second portion to be stored in the second type of storage.   
     
     
         17 . The method as described in  claim 16  including the step of writing data to a file located in a directory which is a policy root directory and has the policy specification. 
     
     
         18 . The method as described in  claim 17  including the steps of looking up a subdirectory D, which is a policy root directory having an associated policy specification, and associating the policy specification with subdirectory D. 
     
     
         19 . A system for storing file data and directory data received over a network comprising:
 a network interface in communication with the network which receives NAS requests from the network, including NAS requests containing data to be written to files;   a first type of storage;   a second type of storage different from the first type of storage;   a policy specification which specifies a first portion of one or more directories' data which is less than all of the directories' data is stored in the first type of storage and a second portion of the data which is less than all of the data of the directories is stored in the second type of store; and   a processing unit which executes the policy and causes the first portion to be stored in the first type of storage and a second portion to be stored in the second type of storage.   
     
     
         20 . A system for storing file data and directory data received over a network comprising:
 a network interface in communication with the network which receives NAS requests containing data to be written to files from the network;   a first type of storage;   a policy specification which specifies a first portion of one or more files' data which is less than all of the files' data is stored in the first type of storage;   a processing unit which executes the policy and causes the first portion to be stored in the first type of storage;   an inode attribute manager which updates attributes in an inode; and   an inode object allocator which allocates inodes and tags them with policy specifications.