Volume or virtual machine level backup and generating placeholders for virtual machine files

Abstract

According to certain aspects, a method can include creating a backup copy of data associated with a virtual machine (VM) on one or more secondary storage devices, wherein the backup copy includes corresponding secondary copies of a plurality of files associated with the VM; analyzing metadata associated with the secondary copies to determine which of the plurality files are eligible to be removed from the primary storage device; in response determining that one or more files are eligible to be removed from the primary storage device, for respective file of the one or more files: determining whether the respective file has been changed since a first time at which the backup copy of the data associated with the VM was created; in response to determining that the respective file has not changed since the first time, removing the respective file; and adding a file placeholder for the removed file.

What is claimed is: 
     
         1 . A method of removing files associated with a virtual machine, the method comprising:
 creating a backup copy of data associated with a virtual machine (VM) on one or more secondary storage devices, wherein the data associated with the VM resides on a primary storage device and comprises a plurality of files associated with the VM, and wherein the backup copy comprises corresponding secondary copies of the plurality of files;   analyzing, using computer hardware, metadata associated with the secondary copies of the plurality of files associated with the VM to determine which of the plurality files are eligible to be removed from the primary storage device; and   in response determining that one or more files of the plurality of files are eligible to be removed from the primary storage device,
 for respective file of the one or more files:
 determining, using computer hardware, whether the respective file has been changed since a first time at which the backup copy of the data associated with the VM was created; 
 in response to determining that the respective file has not changed since the first time, removing the respective file; and 
 adding a file placeholder for the removed file on the primary storage device. 
 
   
     
     
         2 . The method of  claim 1 , wherein:
 the data associated with the VM is included in a volume that resides at least in part on the primary storage device; and   said creating a backup copy of data associated with the VM comprises creating a backup copy of the volume.   
     
     
         3 . The method of  claim 2 , wherein the backup copy of the volume is a snapshot of the volume. 
     
     
         4 . The method of  claim 3 , wherein the snapshot is a hardware snapshot. 
     
     
         5 . The method of  claim 1 , wherein the metadata comprises one or more of: file creation time, file access time, file modification time, file size, file extension, user associated with a file, or application associated with a file. 
     
     
         6 . The method of  claim 1 , wherein said analyzing metadata associated with the secondary copies of the plurality of files associated with the VM comprises determining which of the plurality of files have not been accessed within a period of time. 
     
     
         7 . The method of  claim 1 , wherein said analyzing metadata associated with the secondary copies of the plurality of files associated with the VM comprises determining which of the plurality of files have been accessed fewer times than a threshold value within a period of time. 
     
     
         8 . The method of  claim 1 , wherein criteria for determining which of the plurality files are eligible to be removed are defined as one or more rules. 
     
     
         9 . The method of  claim 1 , wherein said creating a backup copy of data associated with a VM comprises:
 identifying changed blocks since a first time at which a previous backup copy of the data associated with the VM was created; and   copying only the changed blocks to the one or more secondary storage devices.   
     
     
         10 . The method of  claim 9 , wherein a hypervisor associated with the VM identifies the changed blocks. 
     
     
         11 . The method of  claim 9 , wherein a driver marks used blocks to identify the changed blocks. 
     
     
         12 . The method of  claim 9 , wherein the changed blocks are identified by signature comparison. 
     
     
         13 . The method of  claim 1 , wherein the file placeholder comprises a unique identifier associated with the secondary copy of the removed file and an offset associated with the secondary copy of the removed file. 
     
     
         14 . The method of  claim 1 , further comprising, in response to an access of the file placeholder for a removed file, restoring the secondary copy of the removed file from the one or more secondary storage devices to a primary storage device. 
     
     
         15 . An information management system configured to remove files associated with a virtual machine, the system comprising:
 one or more computing devices comprising computer hardware, wherein the one or more computing devices:
 create a backup copy of data associated with a virtual machine (VM) on one or more secondary storage devices, wherein the data associated with the VM resides on a primary storage device and comprises a plurality of files associated with the VM, and wherein the backup copy comprises corresponding secondary copies of the plurality of files; 
 analyze metadata associated with the secondary copies of the plurality of files associated with the VM to determine which of the plurality files are eligible to be removed from the primary storage device; and 
 in response determining that one or more files of the plurality of files are eligible to be removed from the primary storage device,
 for respective file of the one or more files:
 determine whether the respective file has been changed since a first time at which the backup copy of the data associated with the VM was created; 
 in response to determining that the respective file has not changed since the first time, remove the respective file; and 
 add a file placeholder for the removed file on the primary storage device. 
 
 
   
     
     
         16 . The system of  claim 15 , wherein:
 the data associated with the VM is included in a volume that resides at least in part on the primary storage device; and   the one or more computing devices, as part of the creation of the backup copy of the data associated with the VM, create a backup copy of the volume.   
     
     
         17 . The system of  claim 15 , wherein the metadata comprises one or more of: file creation time, file access time, file modification time, file size, file extension, user associated with a file, or application associated with a file. 
     
     
         18 . The system of  claim 15  wherein the one or more computing devices, as part of the analysis of the metadata associated with the secondary copies of the plurality of files associated with the VM, determine which of the plurality of files have not been accessed within a period of time. 
     
     
         19 . The system of  claim 15 , wherein the one or more computing devices, as part of the analysis of the metadata associated with the secondary copies of the plurality of files associated with the VM, determine which of the plurality of files have been accessed fewer times than a threshold value within a period of time. 
     
     
         20 . The system of  claim 15 , wherein criteria for determining which of the plurality files are eligible to be removed are defined as one or more rules.