Method and system for distributed raid implementation

Abstract

Embodiments of the systems and methods disclosed provide a distributed RAID system comprising a set of data banks. More particularly, in certain embodiments of a distributed RAID system each data bank has a set of associated storage media and executes a similar distributed RAID application. Each data bank may have a high speed memory where a write cache is stored. In certain embodiments, a virtualization layer may be executed on a data bank and the distributed RAID application may execute on the virtualization layer. The distributed RAID application may control access to the high speed memory on which the write cache is stored.

1 . A system for implementing distributed RAID, comprising:
 a plurality of storage appliances, each storage appliance coupled to each of the other plurality of storage appliances, each storage appliance including:
 a processor; 
 a data store comprising a first portion and a second portion, wherein the second portion is a high speed memory; 
 a computer readable medium comprising instructions executable to: 
   receive a command corresponding to a first segment of a first volume from a host, wherein:
 the first volume comprises a first set of segments, and the first set of segments of the first volume are stored on the plurality of storage appliances according to a first storage appliance order, where the first storage appliance order is a first ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once, and wherein 
 redundancy data corresponding to a first RAID level implemented in conjunction with the first volume is stored on each of the plurality of storage appliances, such that for each segment of the first volume one or more corresponding redundancy segments comprising the redundancy data associated with that segment of the volume does not reside on the same storage appliance as the corresponding segment of the volume; 
   determine a first storage appliance of the plurality of storage appliances, wherein the first storage appliance corresponds to the first segment; and if the first storage appliance is the storage appliance which received the command execute the first command with respect to the first segment, and   if not, forward the first command to the first storage appliance.   
     
     
         2 . The system of  claim 1 , wherein the first segment is stored on the first portion of the data store or the second portion of the data store based on one or more criteria associated with the first segment. 
     
     
         3 . The system of  claim 2 , wherein the one or more criteria include a quality of service indicator. 
     
     
         4 . The system of  claim 1 , wherein the computer readable medium comprises second instructions executable to implement a virtualization layer, wherein the distributed RAID application executes on the virtualization layer. 
     
     
         5 . The system of  claim 4 , wherein the data store is accessible without use of the virtualization layer. 
     
     
         6 . The system of  claim 1 , wherein a second volume is stored on the plurality of storage appliances according to a second storage appliance order, wherein the second storage appliance order is a second ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once. 
     
     
         7 . The system of  claim 6 , wherein a second RAID level is implemented in conjunction with the second volume. 
     
     
         8 . A method for implementing a distributed RAID application on one or more storage appliances, each storage appliance comprising a processor and a data store comprising a first portion and a second portion, wherein the second portion of the data store is a high speed memory, comprising:
 receiving a command corresponding to a first segment of a first volume from a host, wherein:
 the first volume comprises a first set of segments, and the first set of segments of the first volume are stored on the plurality of storage appliances according to a first storage appliance order, where the first storage appliance order is a first ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once, and wherein 
 redundancy data corresponding to a first RAID level implemented in conjunction with the first volume is stored on each of the plurality of storage appliances, such that for each segment of the first volume one or more corresponding redundancy segments comprising the redundancy data associated with that segment of the volume does not reside on the same storage appliance as the corresponding segment of the volume; 
   determining a first storage appliance of the plurality of storage appliances, wherein the first storage appliance corresponds to the first segment; and   if the first storage appliance is the storage appliance which received the command executing the first command with respect to the first segment, and if not, forwarding the first command to the first storage appliance.   
     
     
         9 . The method of  claim 8 , wherein the first segment is stored on the first portion of the data store or the second portion of the data store based on one or more criteria associated with the first segment. 
     
     
         10 . The method of  claim 9 , wherein the one or more criteria include a quality of service indicator. 
     
     
         11 . The method of  claim 8 , further comprising executing a virtualization layer, wherein the distributed RAID application executes on the virtualization layer. 
     
     
         12 . The method of  claim 11 , wherein the data store is accessible without use of the virtualization layer. 
     
     
         13 . The method of  claim 8 , wherein a second volume is stored on the plurality of storage appliances according to a second storage appliance order, wherein the second storage appliance order is a second ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once. 
     
     
         14 . The method of  claim 13 , wherein a second RAID level is implemented in conjunction with the second volume. 
     
     
         15 . A computer readable medium comprising computer executable instructions for implementing a distributed RAID application on one or more storage appliances, each storage appliance comprising a processor and a data store comprising a first portion and a second portion, wherein the second portion of the data store is a high speed memory, the computer instructions executable for:
 receiving a command corresponding to a first segment of a first volume from a host, wherein:
 the first volume comprises a first set of segments, and the first set of segments of the first volume are stored on the plurality of storage appliances according to a first storage appliance order, where the first storage appliance order is a first ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once, and wherein 
 redundancy data corresponding to a first RAID level implemented in conjunction with the first volume is stored on each of the plurality of storage appliances, such that for each segment of the first volume one or more corresponding redundancy segments comprising the redundancy data associated with that segment of the volume does not reside on the same storage appliance as the corresponding segment of the volume; 
   determining a first storage appliance of the plurality of storage appliances, wherein the first storage appliance corresponds to the first segment; and   if the first storage appliance is the storage appliance which received the command executing the first command with respect to the first segment, and if not, forwarding the first command to the first storage appliance.   
     
     
         16 . The computer readable medium of  claim 15 , wherein the first segment is stored on the first portion of the data store or the second portion of the data store based on one or more criteria associated with the first segment. 
     
     
         17 . The computer readable medium of  claim 16 , wherein the one or more criteria include a quality of service indicator. 
     
     
         18 . The computer readable medium of  claim 15 , further comprising instructions for executing a virtualization layer, wherein the distributed RAID application executes on the virtualization layer. 
     
     
         19 . The computer readable medium of  claim 18 , wherein the data store is accessible without use of the virtualization layer. 
     
     
         20 . The computer readable medium of  claim 15 , wherein a second volume is stored on the plurality of storage appliances according to a second storage appliance order, wherein the second storage appliance order is a second ordering of the plurality of storage appliances including each of the plurality of storage appliances exactly once. 
     
     
         21 . The computer readable medium of  claim 20 , wherein a second RAID level is implemented in conjunction with the second volume.