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 VMware ESXi/vCenter backup sets from AhsayOBM v9.1.0.0 or above. AhsayOBM makes use of Granular Restore technology to enable a file level restore from a virtual disk file (VDDK) 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 on 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 virtual machine. 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, i.e. 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?

Benefits of Using Granular Restore

Comparison between Granular Restore and Traditional Restore:

• Granular Restore

  Granular Restore
  Introduction
  Pros
  Cons
  Granular restore allows you to quickly mount virtual disk(s) directly from the backup file of a guest VM, so that individual files from virtual disk(s) can be exposed via the file explorer on AhsayOBM, or to be copied from the file explorer on to a 64 bit Windows machine you are performing the restore.
  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 VMware 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.
  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
  Pros
  Cons
  The traditional restore method for guest VMs, restores the entire backup files to either 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.
  Backup with Compression and Encryption	Guest VM is encrypted and compressed, therefore is in smaller file size, and encrypted before being uploaded to the backup destination.
  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 CAL (client access licenses) are required.

Requirements

Supported Backup Modules

Granular restore is supported on VMware backup sets created and backed up using AhsayOBM v9.1.0.0 or above installed on a Windows platform with the Granular Restore feature enabled on the backup set.

License Requirements

An OpenDirect / Granular Restore add-on module license is required for this feature to work. Contact your backup service provider for more details.

Backup Quota Storage

As compression is not enabled for Granular backup sets, to optimize restore performance, the storage quota required will be higher than non-Granular backup sets. Contact your backup service provider for details.

Operating System

AhsayOBM must be installed on a 64-bit Windows machine as libraries for Granular only supports 64-bit Windows operating system for VMware ESXi/vCenter. Refer to the following article for the list of compatible operating system for Granular Restore:

Software Compatibility List for Granular and OpenDirect Restore on v9.

For VMware ESXi/vCenter 7 backups, AhsayOBM must be installed on the following Windows versions:

Temporary Directory Requirement

The temporary directory folder should have at least the same available size as the guest VM to be restored and should be located on a local drive to ensure optimal backup/restore performance.

Network Drive Requirements

The login accounts for network drives must have read and write access permission to ensure that backup and restore would be successful.

Available Spare Drive Letter

One spare drive letter must be available on the Windows machine for the Granular Restore process, as the VDDK virtual disk is mounted on Windows as a logical drive. AhsayOBM will automatically take the next available drive letter in alphabetical order for the mounted virtual disk.

Network Requirements

The recommended minimum network speed is at Least 100Mbps download speed.

The network bandwidth requirements will increase in proportion to the size of the guest VM and the incremental delta chain length to ensure optimal performance. Working with limited network bandwidth may severely affect the granular restore performance.

You can use an online network speed test website to get an idea of the actual bandwidth of the machine.

Other Dependencies

The following dependencies are restore-related and therefore they will be checked by AhsayOBM only when granular restore is performed. Absence of these elements will not affect the backup job but would cause the restore to fail.

• Microsoft Visual C++ 2015 Redistributable (x86)/(x64)
• Update for Universal C Runtime in Windows
• For WIndows 7 and WIndows Server 2008 R2 only

Permissions

• The Windows login account used for installation and operation of the AhsayOBM client machine requires Administrator privileges.
• For Granular Restore, Windows User Account Control (UAC) must be disabled.
• For Granular Restore (OpenDirect), it is required to log in as the real Windows administrator and not any other user with admin role or with elevated admin account permission. The real administrator account will be the one with the security identifier (SID) "S-1-5-21domain-500".

Limitations

• Network drives which have not been setup or mapped in Windows are not supported.
• Temporary folder location is not supported with individual login credentials but can still be setup separately using existing Windows User Authentication login.
• It also does not support Pre-Backup and Post-Backup Commands.
• Not supported on "Restore Raw file" and "Restore to local computer" options.