Failover systems and methods for performing backup operations

Abstract

In certain embodiments, a tiered storage system is disclosed that provides for failover protection during data backup operations. The system can provide for an index, or catalog, for identifying and enabling restoration of backup data located on a storage device. The system further maintains a set of transaction logs generated by media agent modules that identify metadata with respect to individual data chunks of a backup file on the storage device. A copy of the catalog and transaction logs can be stored at a location accessible by each of the media agent modules. In this manner, in case of a failure of one media agent module during backup, the transaction logs and existing catalog can be used by a second media agent module to resume the backup operation without requiring a restart of the backup process.

What is claimed is: 
     
         1 . A method for performing an operation in a data storage system, the method comprising:
 with a first computing device comprising one or more hardware processors:
 receiving a plurality of data units from a client computing device to store on at least one first storage device as part of a data protection operation; 
 storing at least one data unit of the plurality of data units on the at least one first storage device; and 
 prior to completion of the data protection operation, storing metadata to at least one second storage device in association with said storing of the at least one data unit and prior to, concurrently with, or subsequent to said storing of the at least one data unit; and 
   with a second computing device comprising one or more hardware processors:
 receiving an instruction to take over control of the data protection operation; 
 obtaining the metadata associated with the storing of the at least one data unit from the at least one second storage device; 
 using at least the metadata, determining a point in the data protection operation at which the first computing device ceased performance of the data protection operation; and 
 using the determined point in the data protection operation to resume performance of the data protection operation at least partly by storing on the at least one first storage device at least one other data unit which has not yet been stored on the at least one first storage device, and without repeating the storage of the at least one data unit on the at least one first storage device. 
   
     
     
         2 . The method of  claim 1 , further comprising, with the second computing device and prior to resuming performance of the data protection operation:
 obtaining an index associated with the data protection operation;   applying at least the metadata to the index to create an updated index; and   storing the updated index.   
     
     
         3 . A data storage system for performing an operation, comprising:
 a first computing device comprising one or more hardware processors, wherein the first computing device is configured to:
 receive a plurality of data units from a client computing device to store on at least one first storage device as part of a data protection operation; 
 store at least one data unit of the plurality of data units on the at least one first storage device; and 
 prior to completion of the data protection operation, storing metadata to at least one second storage device in association with said storing of the at least one data unit and prior to, concurrently with, or subsequent to said storing of the at least one data unit; and 
   a second computing device comprising one or more hardware processors, wherein the second computing device is configured to:
 receive an instruction to take over control of the data protection operation; 
 obtain the metadata associated with the storing of the at least one data unit from the at least one second storage device; 
 using at least the metadata, determine a point in the data protection operation at which the first computing device ceased performance of the data protection operation; and 
 using the determined point in the data protection operation to resume performance of the data protection operation at least partly by storing on the at least one first storage device at least one other data unit which has not yet been stored on the at least one first storage device, and without repeating the storage of the at least one data unit on the at least one first storage device. 
   
     
     
         4 . The data storage system of  claim 3 , wherein the second computing device is further configured to, prior to resuming performance of the data protection operation:
 obtain an index associated with the data protection operation;   apply at least the metadata to the index to create an updated index; and   store the updated index.   
     
     
         5 . A non-transitory computer readable medium comprising code that, when executed, causes:
 a first computing device comprising one or more hardware processors to:
 receive a plurality of data units from a client computing device to store on at least one first storage device as part of a data protection operation; 
 store at least one data unit of the plurality of data units on the at least one first storage device; and 
 prior to completion of the data protection operation, storing metadata to at least one second storage device in association with said storing of the at least one data unit and prior to, concurrently with, or subsequent to said storing of the at least one data unit; and 
   a second computing device comprising one or more hardware processors to:
 receive an instruction to take over control of the data protection operation; 
 obtain the metadata associated with the storing of the at least one data unit from the at least one second storage device; 
 using at least the metadata, determine a point in the data protection operation at which the first computing device ceased performance of the data protection operation; and 
 using the determined point in the data protection operation to resume performance of the data protection operation at least partly by storing on the at least one first storage device at least one other data unit which has not yet been stored on the at least one first storage device, and without repeating the storage of the at least one data unit on the at least one first storage device. 
   
     
     
         6 . The computer readable medium of  claim 5 , wherein the code further causes the second computing device to, prior to resuming performance of the data protection operation:
 obtain an index associated with the data protection operation;   apply at least the metadata to the index to create an updated index; and   store the updated index.