Using a pseudo-disk driver for indexing contents and metadata of block-level backup copies, including block-level backup copies of virtual machine data files

Abstract

A streamlined approach analyzes block-level backups of VM virtual disks and creates both coarse and fine indexes of backed up VM data files in the block-level backups. The indexes (collectively the “content index”) enable granular searching by filename, by file attributes (metadata), and/or by file contents, and further enable granular live browsing of backed up VM files. Thus, by using the illustrative data storage management system, ordinary block-level backups of virtual disks are “opened to view” through indexing. Any block-level copies can be indexed according to the illustrative embodiments, including file system block-level copies. The indexing occurs offline in an illustrative data storage management system, after VM virtual disks are backed up into block-level backup copies, and therefore the indexing does not cut into the source VM's performance. The disclosed approach is widely applicable to VMs executing in cloud computing environments and/or in non-cloud data centers. The illustrative content indexing is accomplished without restoring the VM data files being indexed to a staging location.

What is claimed is: 
     
         1 . A method for using one or more pseudo-disk drivers to index backup copies of virtual machine data files in a data storage management system, the method comprising:
 by a computing device, activating a pseudo-disk driver that corresponds to a point in time associated with a plurality of block-level backup copies of virtual machine data files in a virtual machine disk at or before the point in time,
 wherein the backup copies were generated by a media agent component of the data storage management system, 
 wherein the computing device comprises one or more hardware processors, and wherein the media agent comprises one or more hardware processors; 
   by the pseudo-disk driver, implementing a pseudo-disk in cache memory at the computing device;   by the pseudo-disk driver, causing the pseudo-disk to be mounted at the computing device as a data storage volume designated for the plurality of block-level backup copies;   by the pseudo-disk driver, receiving from a file manager application executing on the computing device first read requests for metadata in the plurality of block-level backup copies;   by the pseudo-disk driver, if unable to serve one of the first read requests from the pseudo-disk, transmitting a second read request to the media agent;   by the media agent, identifying based on the second read request metadata in the plurality of block-level copies that is current as of the point in time;   by the media agent, responding to the second read request by recalling the identified metadata from one or more of the plurality of block-level copies without restoring the virtual machine data files in their entireties to the pseudo-disk; and   by the computing device, generating an index of the virtual machine data files in the virtual machine disk as of the point in time, wherein the index comprises filenames and file attributes in metadata stored in the pseudo-disk and obtained by the file manager application from the plurality of block-level copies using the pseudo-disk driver.   
     
     
         2 . The method of  claim 1 , wherein the index enables searching for individual files among the virtual machine data files. 
     
     
         3 . The method of  claim 1 , wherein a storage manager that manages storage operations in the data storage management system instructs the computing device to activate the pseudo-disk driver to correspond to the point in time associated with the plurality of block-level backup copies of the virtual machine data files, and
 wherein the storage manager comprises one or more hardware processors.   
     
     
         4 . The method of  claim 1 , further comprising:
 by the media agent, storing the metadata recalled from the one or more of the plurality of block-level copies to the pseudo-disk.   
     
     
         5 . The method of  claim 1 , further comprising:
 by the media agent, storing the metadata recalled from the one or more of the plurality of block-level copies to the pseudo-disk; and   by the pseudo-disk driver, serving one of the first read requests from the pseudo-disk if responsive metadata is stored therein.   
     
     
         6 . The method of  claim 1 , wherein the data storage volume designated for the plurality of block-level backup copies comprises metadata recalled from one or more of the plurality of block-level copies but does not comprise restored virtual machine data files in their entireties. 
     
     
         7 . The method of  claim 1 , wherein the pseudo-disk comprises metadata recalled from one or more of the plurality of block-level copies but does not comprise restored virtual machine data files in their entireties. 
     
     
         8 . The method of  claim 1 , wherein the pseudo-disk driver is one of a plurality of pseudo-disk drivers at the computing device, and wherein each pseudo-disk driver corresponds to a distinct point in time associated with a corresponding plurality of block-level backup copies of virtual machine data files in the virtual machine disk at or before the distinct point in time, and further comprising:
 by the computing device, generating a distinct index of the virtual machine data files as of the distinct point in time,
 wherein the distinct index comprises filenames and file attributes in metadata obtained by the file manager application from the corresponding plurality of block-level copies using one of the plurality of pseudo-disk drivers that corresponds to the distinct point in time. 
   
     
     
         9 . The method of  claim 1  further comprising:
 by the computing device, selecting one of the virtual machine data files tracked by the index; 
 by the media agent, restoring to the pseudo-disk from the plurality of block-level backup copies, individual portions of the one virtual machine data file that the media agent determines to be current as of the point in time, wherein the individual portions are restored without restoring the one virtual machine data file in its entirety to the pseudo-disk; 
 by the computing device, applying content criteria to each individual portion in the pseudo-disk to identify content in the one virtual machine data file at the point in time that matches the content criteria; and 
 by the computing device, generating a second index that tracks the identified content that matches the content criteria, wherein the second index enables searching for content among the virtual machine data files in the virtual machine disk as of the point in time, based on the plurality of block-level backup copies. 
 
     
     
         10 . The method of  claim 1 , wherein the pseudo-disk driver stores data included in write commands issued by the file manager application without making changes to the plurality of block-level backup copies; and
 by the computing device, after the index is generated with respect to the point in time, causing the pseudo-disk to be discarded, including the data included in the write commands issued by the file manager application.   
     
     
         11 . A data storage management system for using one or more pseudo-disk drivers to index backup copies of virtual machine data files, the system comprising:
 a computing device comprising one or more hardware processors;   a media agent in communication with the computing device and comprising one or more hardware processors;   a storage manager in communication with the computing device and with the media agent, and comprising one or more hardware processors;   wherein the computing device is configured to:
 activate a pseudo-disk driver at the computing device that corresponds to a point in time associated with a plurality of block-level backup copies of virtual machine data files in a virtual machine disk at or before the point in time, 
 wherein a storage operation managed by the storage manager generated the backup copies, which were stored by the media agent to a storage device; 
 by the pseudo-disk driver, implement a pseudo-disk in cache memory at the computing device; 
 by the pseudo-disk driver, cause the pseudo-disk to be mounted at the computing device as a data storage volume designated for the plurality of block-level backup copies; 
 by the pseudo-disk driver, receive from a file manager application executing on the computing device first read requests for metadata in the plurality of block-level backup copies; 
 by the pseudo-disk driver, if unable to serve one of the first read requests from the pseudo-disk, transmit a second read request to the media agent; 
   wherein the media agent is configured to:
 identify based on the second read request metadata in the plurality of block-level copies that is current as of the point in time, and 
 respond to the second read request by recalling the identified metadata from one or more of the plurality of block-level copies at the storage device without restoring the virtual machine data files in their entireties to the pseudo-disk at the computing device; and 
   wherein the computing device is further configured to generate an index of the virtual machine data files in the virtual machine disk as of the point in time, wherein the index comprises filenames and file attributes in metadata stored in the pseudo-disk and obtained by the file manager application from the plurality of block-level copies using the pseudo-disk driver.   
     
     
         12 . The system of  claim 11 , wherein the index enables searching for individual files among the virtual machine data files. 
     
     
         13 . The system of  claim 11 , wherein the storage manager is configured to instruct the computing device to activate the pseudo-disk driver to correspond to the point in time associated with the plurality of block-level backup copies of the virtual machine data files. 
     
     
         14 . The system of  claim 11 , wherein the media agent is further configured to store the metadata recalled from the one or more of the plurality of block-level copies to the pseudo-disk. 
     
     
         15 . The system of  claim 11 , wherein the media agent is further configured to store the metadata recalled from the one or more of the plurality of block-level copies to the pseudo-disk; and
 wherein the computing device is further configured to: by the pseudo-disk driver, serve one of the first read requests from the pseudo-disk if responsive metadata is stored therein.   
     
     
         16 . The system of  claim 11 , wherein the data storage volume designated for the plurality of block-level backup copies comprises metadata recalled from one or more of the plurality of block-level copies but does not comprise restored virtual machine data files in their entireties. 
     
     
         17 . The system of  claim 11 , wherein the pseudo-disk comprises metadata recalled from one or more of the plurality of block-level copies but does not comprise restored virtual machine data files in their entireties. 
     
     
         18 . The system of  claim 11 , wherein the pseudo-disk driver is one of a plurality of pseudo-disk drivers at the computing device, and wherein each pseudo-disk driver corresponds to a distinct point in time associated with a corresponding plurality of block-level backup copies of virtual machine data files in the virtual machine disk at or before the distinct point in time, and
 wherein the computing device is further configured to generate a distinct index of the virtual machine data files as of the distinct point in time,
 wherein the distinct index comprises filenames and file attributes in metadata obtained by the file manager application from the corresponding plurality of block-level copies using one of the plurality of pseudo-disk drivers that corresponds to the distinct point in time. 
   
     
     
         19 . The system of  claim 11 , wherein the media agent is further configured to restore to the pseudo-disk from the storage device, individual portions of one virtual machine data file that the media agent determines to be current as of the point in time, and
 wherein the individual portions are restored without restoring the one virtual machine data file in its entirety to the pseudo-disk; and   wherein the computing device is further configured to:   apply content criteria to each individual portion in the pseudo-disk to identify content in the one virtual machine data file at the point in time that matches the content criteria, and   generate a second index that tracks the identified content that matches the content criteria, wherein the second index enables searching for content among the virtual machine data files in the virtual machine disk as of the point in time, based on using the pseudo-disk driver.   
     
     
         20 . The system of  claim 11 , wherein the pseudo-disk driver stores data included in write commands issued by the file manager application without making changes to the plurality of block-level backup copies; and
 wherein the computing device is further configured to, after the index is generated with respect to the point in time, cause the pseudo-disk to be discarded, including the data included in the write commands issued by the file manager application.