Use the Latest Version

The latest version of AhsayOBM must be installed on the Hyper-V server. For Hyper-V Cluster environment the latest version of AhsayOBM must be installed on all Cluster nodes.

Modules

AhsayOBM user account created on AhsayCBS must have sufficient Hyper-V add-on modules or CPU sockets assigned. Hyper-V Cluster backup sets will require one AhsayOBM license per node.

Sufficient Quota

AhsayOBM user account has sufficient quota assigned to accommodate the storage of the guest virtual machines. (Please contact your backup service provider for details).

Hyper-V guest virtual machines contain three types of virtual disks:

• Fixed Hard Disk.
• Dynamic Hard Disk.
• Differencing Hard Disk.

When AhsayOBM backs up a Hyper-V guest virtual machines for an initial or subsequent full backup jobs:

• Using fixed Hard Disks it will back up the provisioned size, e.g. for a 500GB fixed virtual hard disk 500GB will be backed up to the storage designation.
• Using Dynamic Hard Disk or Differencing Hard Disk it will back up the used size, e.g. for a 500GB fixed virtual hard disk, 20GB will backed up to the storage designation if only 20GB are used.

Proper Java heap size configured

The default Java heap size setting on AhsayOBM is 2048MB, for Hyper-V backups it is highly recommended to increase the Java heap size setting to improve backup and restore performance. (The actual heap size is dependent on amount of free memory available on your Hyper-V server).

Delta generation of large VHD files is a memory intensive process; therefore, it is recommended that the Java heap size to be at least 2048MB - 4096MB. The actual required Java heap size is subject to various factors including files size, delta mode, backup frequency, etc.

Refer to this KB article for how to configure Java heap size on your AhsayOBM.

Temporary directory

For stand-alone Hyper-V server, AhsayOBM uses the temporary folder for storing backup set index files and any incremental or differential delta files generated during a backup job. To ensure optimal backup / restore performance, it should be located on a local drive with plenty of free disk space. It should not be on the Windows system C:\ drive.

NOTE
For Hyper-V server in Failover Cluster environment:
- Hyper-V server 2008 / 2008 R2 and 2012 / 2012 R2 the temporary directory must be set to a local drive of the cluster node.
- Hyper-V server 2016 / 2019  the temporary directory must be set to the Cluster Shared Volume (CSV).

AhsayOBM UI during Run Direct restore or migration

AhsayOBM UI must be running when a guest virtual machine is started using Run Direct Restore or when migration process is running.

NFS server

Make sure NFS service has started for Run Direct to operate. If the backup destination is located on network drive, the logon account must have sufficient permission to access the network resources.

Administrator permission

The operating system account for setting up the Hyper-V / Hyper-V Cluster backup set must have administrator permission (e.g. administrative to access the cluster storage).

Windows User Account Control

For Granular Restore, Windows User Account Control (UAC) must be disabled.

Compression

For local, mapped drive, or removable drive storage destinations with Run Direct enabled, the compression type will always be set to No Compression and data encryption is disabled to ensure optimal backup and restore performance. The backup set compression type and data encryption settings will only be applied to CBS, SFTP/FTP, or Cloud storage destinations.

Backup whole VM

For ease of restore it is recommended to back up the whole guest machine (all the virtual disks) rather than individual virtual disks.

Hyper-V management tools

The Hyper-V management tools are installed on the server. For Hyper-V Cluster environments Hyper-V management tools is installed on all Cluster nodes.

Hyper-V services

The Hyper-V services are started on the server. For Hyper-V Cluster environments the Hyper-V services are started on all Cluster nodes.

Example: Windows 2008 R2 Hyper-V

Hyper-V VSS Writer

The Microsoft Hyper-V VSS Writer is installed and running on the Hyper-V server and the writer state is Stable. This can be verified by running the vssadmin list writers command.

Example:

C:\Users\Administrator>vssadmin list writers
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.
Writer name: 'Task Scheduler Writer'
   Writer Id: {d61d61c8-d73a-4eee-8cdd-f6f9786b7124}
   Writer Instance Id: {1bddd48e-5052-49db-9b07-b96f96727e6b}
   State: [1] Stable
   Last error: No error

Writer name: 'VSS Metadata Store Writer'
   Writer Id: {75dfb225-e2e4-4d39-9ac9-ffaff65ddf06}
   Writer Instance Id: {088e7a7d-09a8-4cc6-a609-ad90e75ddc93}
   State: [1] Stable
   Last error: No error

Writer name: 'Performance Counters Writer'
   Writer Id: {0bada1de-01a9-4625-8278-69e735f39dd2}
   Writer Instance Id: {f0086dda-9efc-47c5-8eb6-a944c3d09381}
   State: [1] Stable
   Last error: No error

Writer name: 'System Writer'
   Writer Id: {e8132975-6f93-4464-a53e-1050253ae220}
   Writer Instance Id: {8de7ed2b-8d69-43dd-beec-5bfb79b9691c}
   State: [1] Stable
   Last error: No error

Writer name: 'SqlServerWriter'
   Writer Id: {a65faa63-5ea8-4ebc-9dbd-a0c4db26912a}
   Writer Instance Id: {1f668bf9-38d6-48e8-81c4-2df60a3fab57}
   State: [1] Stable
   Last error: No error

Writer name: 'ASR Writer'
   Writer Id: {be000cbe-11fe-4426-9c58-531aa6355fc4}
   Writer Instance Id: {01499d55-61da-45bc-9a1e-76161065630f}
   State: [1] Stable
   Last error: No error

Writer name: 'Microsoft Hyper-V VSS Writer'
   Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
   Writer Instance Id: {a51919e3-0256-4ecf-8530-2f600de6ea68}
   State: [1] Stable
   Last error: No error

Writer name: 'COM+ REGDB Writer'
   Writer Id: {542da469-d3e1-473c-9f4f-7847f01fc64f}
   Writer Instance Id: {7303813b-b22e-4967-87a3-4c6a42f861c4}
   State: [1] Stable
   Last error: No error

Writer name: 'Shadow Copy Optimization Writer'
   Writer Id: {4dc3bdd4-ab48-4d07-adb0-3bee2926fd7f}
   Writer Instance Id: {d3199397-ec58-4e57-ad04-e0df345b5e68}
   State: [1] Stable
   Last error: No error

Writer name: 'Registry Writer'
   Writer Id: {afbab4a2-367d-4d15-a586-71dbb18f8485}
   Writer Instance Id: {25428453-2ded-4204-800f-e87204f2508a}
   State: [1] Stable
   Last error: No error

Writer name: 'BITS Writer'
   Writer Id: {4969d978-be47-48b0-b100-f328f07ac1e0}
   Writer Instance Id: {78fa3f1e-d706-4982-a826-32523ec9a305}
   State: [1] Stable
   Last error: No error

Writer name: 'WMI Writer'
   Writer Id: {a6ad56c2-b509-4e6c-bb19-49d8f43532f0}
   Writer Instance Id: {3efcf721-d590-4e50-9a37-845939ca51e0}
   State: [1] Stable
   Last error: No error

Integration Service

• If Integration services is not installed / updated on a guest virtual machine or the guest operating system is not supported by Integration Services, the corresponding virtual machine will be paused or go into a saved state during the snapshot process for both backup and restore, and resume when the snapshot is completed. Furthermore, the corresponding virtual machine uptime will also be reset to 00:00:00 in the Hyper-V Manager.
• Installing or updating Integration Services guest virtual machine(s) may require a restart of the guest virtual machine to complete the installation.
  

  • To install Integration Services
  • In Hyper-V Manager connect to the guest virtual machine and select Action > Insert Integration Services Setup disk
    Example: Windows 7 Enterprise guest
    
  • If the guest operating system supports live virtual machine backup the Backup (volume snapshot) is enabled.
    
  • The related Integration Services are running on the guest virtual machine:
    Example: Windows 7 Enterprise guest
    
    Example: CentOS 6.4 Linux guest
    To check if Linux Integration Services is running on the Linux guest:
    

     # lsmod | grep hv
     
    hv_netvsc            23667  0
    hv_utils             7012  0
    hv_storvsc           10022  2
    hv_vmbus             91567  4 hv_netvsc,hv_utils,hid_hyperv,hv_storvsc
    
    # ps -ef|grep hv
    root       267     2  0 18:07 ?        00:00:00 [hv_vmbus_con/0]
    root       268     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       269     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       270     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       271     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       272     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       273     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       274     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       275     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       276     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root       277     2  0 18:07 ?        00:00:00 [hv_vmbus_ctl/0]
    root      1174     1  0 18:07 ?        00:00:00 /usr/sbin/hv_kvp_daemon
    root      1185     1  0 18:07 ?        00:00:00 /usr/sbin/hv_vss_daemon
    root      1332  1316  0 18:11 pts/0    00:00:00 grep hv

  • Please refer to the following articles for further details on:

    • Considerations for backing up and restoring virtual machines
      https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn798286(v=ws.11)

    • Supported Windows Guest Operating Systems for Hyper-V in Windows Server 2012
      https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn792028(v=ws.11)

    • Supported Windows Guest Operating Systems for Hyper-V in Windows Server 2012 R2
      https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn792027(v=ws.11)

    • Supported Linux and FreeBSD virtual machines for Hyper-V on Windows
      https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/Supported-Linux-and-FreeBSD-virtual-machines-for-Hyper-V-on-Windows

    • Supported CentOS and Red Hat Enterprise Linux virtual machines on Hyper-V
      https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/supported-centos-and-red-hat-enterprise-linux-virtual-machines-on-hyper-v

    • Supported Ubuntu virtual machines on Hyper-V
      https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/supported-ubuntu-virtual-machines-on-hyper-v

    • Linux Integration Services Version 4.0 for Hyper-V
      https://rlevchenko.com/2015/08/18/linux-integration-services-version-4-0-for-hyper-v/

    • Managing Hyper-V Integration Services
      https://msdn.microsoft.com/en-us/virtualization/hyperv_on_windows/user_guide/managing_ics

    • Hyper-V on Window Server
      https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/hyper-v-on-windows-server

Hyper-V 2008 R2

For Hyper-V 2008 R2 server in order to use Run Direct restore feature the “Microsoft Security Advisory 3033929” security update must be installed.

Please refer to the following KB article from Microsoft for further details: https://support.microsoft.com/en-us/kb/3033929

Run Direct Hyper-V Cluster

For Run Direct Hyper-V Cluster backup sets the storage destination must be accessible by all Hyper-V nodes.

Hyper-V Cluster

For Hyper-V Cluster backup sets the guest virtual machines must be created and managed by the Failover Cluster Manager.

VM Snapshot

The VM snapshot method is the preferred backup option, as it supports live guest VM backups. This means guest VM will not be put into a saved state when a VSS snapshot is taken during a backup job. So it will not affect the availability of any applications or services running on the guest VM every time a backup job is performed.

Saved State

If any of the VM Snapshot method requirements cannot be fulfilled, AhsayOBM will automatically use the Save State method. When the Saved State method is used, the guest VM is placed into a saved state while the VSS snapshot is created (effectively shut down), and the duration is dependent on the size of VM and performance of Hyper-V host. The downside is it may affect the availability of any applications or services running on the guest VM every time a backup job is performed.

i. This can be verified by running the net start CBTFilter command.

C:\Users\Administrator>net start CBTFilter
The requested service has already been started.

More help is available by typing NET HELPMSG 2182.

ii. Note: For Windows Server 2008 R2, if the following error is displayed

C:\Users\Administrator>net start CBTFilter
System error 577 has occurred.

Windows cannot verify the digital signature for this file. A recent hardware or software change might have installed a file that is signed incorrect or damaged, or that might be malicious software from an unknown source.

The issue may be related to the availability of SHA-2 code signing support for Windows Server 2008 R2 (https://technet.microsoft.com/en-us/library/security/3033929).

To resolve the issue, install the following patch from Microsoft https://www.microsoft.com/en-us/download/confirmation.aspx?id=46083

Restart the affected server afterward for AhsayOBM to operate properly.

RCT Requirement

1. AhsayOBM would not install CBT Cluster Services (Ahsay Online Backup Manager) but use the native built-in RCT (Resilient Change Tracking) feature of Windows server 2016 and 2019 instead.

2. The guest virtual machine version in Hyper-V must be 8.0 or above.

Example:

get–VM | format–table name, version

Update-VMversion <vmname>

Please refer to the following link of Microsoft for details about virtual machine version: https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/deploy/Upgrade-virtual-machine-version-in-Hyper-V-on-Windows-or-Windows-Server

Guest VM Dependencies Requirements

To get full use of Hyper-V, install the appropriate linux-tools and linux-cloud-tools packages to install tools and daemons, e.g. VSS Snapshot Daemon, for use with virtual machines. Please refer to the following link for the details of requirements for Ubuntu relating to Hyper-V daemons: https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/supported-ubuntu-virtual-machines-on-hyper-v

Supported Backup Modules

Granular restore is supported on Hyper-V backup sets created and backed up using AhsayOBM 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 per backup set 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. AhsayOBM must be installed on the following Windows Operating Systems:

Temporary Directory Requirement

1 . For Hyper-V server 2008 / 2008 R2 / 2012 / 2012 R2 / 2016 / 2019 in a Non Cluster environment, the temporary directory must be set to a local drive on the Hyper-V server.

2. For Hyper-V server in Failover Cluster environment: - Hyper-V server 2008 / 2008 R2 and 2012 / 2012 R2 the temporary directory must be set to a local drive of the cluster node. - Hyper-V server 2016 / 2019 the temporary directory must be set to the Cluster Shared Volume (CSV).

The temporary directory should have at least the same available size as the guest VM to be restored.

Available Spare Drive Letter

One spare drive letter must be available on the Windows machine for the granular restore process, as the VHD 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

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 or 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 (e.g. www.speedtest.net) to get an idea of the actual bandwidth of the machine.

Other Dependencies

The following dependencies are required for restore and therefore they are verified by AhsayOBM only when a granular restore is performed. Absence of these dependencies will not affect the backup job but would cause the granular restore to fail.

• Microsoft Visual C++ 2015 Redistributable (x86) / (x64)
  https://www.microsoft.com/en-us/download/details.aspx?id=48145
• Update for Universal C Runtime in Windows
  https://support.microsoft.com/en-us/help/2999226/update-for-universal-c-runtime-in-windows

Permissions

The Windows login account used for installation and operation of the AhsayOBM client machine requires Administrator privileges.