Granular Restore Technology

AhsayOBM Granular Restore technology enables the recovery of individual files from a guest VM without booting up or restoring the whole guest VM first.

Granular restore is one of the available restore options for Hyper-V backup sets. AhsayOBM makes use of Granular Restore technology to enable a file level restore from a virtual disk file (VHD) of guest VM backup possible. It is particularly useful if you only need to restore individual file(s) from a guest VM which would normally take a long time to restore and then startup before you can gain access to the files on the virtual disks. Granular restore gives you a fast and convenient way to recover individual files from a guest VM.

During the Granular Restore process, the virtual disks of the guest VM can be mounted on the Windows machine as a local drive. This will allow the individual files on the virtual disks to be viewed via the file explorer within AhsayOBM or from the Windows File Explorer on the Windows machine you are performing the restore on, without having to restore the entire VM. Granular restore can only mount virtual disks if the guest VM is running on a Windows platform and it is supported for all backup destinations, e.g. AhsayCBS, Cloud storage, or Local/Network drives. The mounting of Linux/Unix file systems from virtual disk file is currently not available due to limitations of the file system drivers.

How Does Granular Restore Work

Comparison Between Granular Restore and Traditional Restore

• Granular Restore

  Granular Restore
  Introduction
  Pros
  Restore of Entire Guest VM Not Required	Compared to a traditional restore where you have to restore the entire guest VM first, before you can access any individual files/folders, Granular Restore allows you to view and download individual files, without having to restore the entire guest VM first.
  Ability to Restore Selected Files	In some cases, you may only need to restore a few individual file(s) from the guest VM, therefore, Granular Restore gives you a fast, convenient, and flexible tool to restore selected file(s) from a guest VM quickly.
  Only One Backup Set Required	With traditional restore methods, if you wish to restore individual file(s) from a guest VM, you will have to create two different backup sets; a Hyper-V guest VM backup set and a separate file backup set for the file(s) you wish to restore. You will require an additional AhsayOBM installation on the guest VM environment, with Granular Restore feature, only one backup set is required. Fewer CAL (Client Access License) required - you will only need one AhsayOBM CAL to perform guest VM, Run Direct, and Granular restore. Less storage space required - as you only need to provision storage for one backup set. Less backup time required - As only one backup job needs to run. Less time spent on administration - As there are fewer backup sets to maintain.
  Cons
  No Encryption and Compression	To ensure optimal restore performance, the backup of the guest VM will NOT be encrypted and compressed, therefore, you may have to take this factor in consideration when using this restore method.

• Traditional Restore

  Traditional Restore
  Introduction
  The traditional restore method for guest VMs, restores the entire backup files either to the original VM location or another standby location. The files or data on the guest VM can only be accessed once the guest VM has been fully recovered and booted up.
  Pros
  Backup with Compression and Encryption	Guest VM is encrypted and compressed, therefore is in a smaller file size, and encrypted before being uploaded to the backup destination.
  Cons
  Slower Recovery	As the entire guest VM has to be restored before you can access any of its file(s) or data, the restore time could be long if the guest VM size is large.
  Two Backup Sets and CALs Required	If you only wish to restore individual files from VM, two separate backup sets are required, one for the VM image and the other for the individual files, and therefore two CALs (client access licenses) are required.