Requirements

VMware vCenter/ESXi Requirements

For backup of virtual machines on vCenter / ESXi servers, make sure the following requirements are met.

ESXi/vCenter Patch Release

Make sure that the latest supported patch release is installed on the vCenter / ESXi hosts to prevent critical issue, such as corruption to change tracking data in certain situation (QueryChangedDiskAreas API returns incorrect sectors after extending virtual machine VMDK file with Changed Block Tracking (CBT) enabled in ESXi 8.0u2)

ESXi Shell Access

• ESXi Shell access must be enabled on the ESXi servers. Refer to the following VMware KB article for instruction: Using ESXi Shell in ESXi 6.x, 7.x, and 8.x
• Consult with VMware support representatives if you are unsure on the process.

License Specification

• Paid License (VMware Essentials License or above): VMware ESXi and vCenter v5.5, v6, v6.5, v6.7, and v7.
• Free License: VMware ESXi v5.5, v6, v6.5, v6.7

SSH

SSH must be enabled on the hypervisor (ESXi Server). To enable root SSH login on an ESXi host, please follow the below instructions from VMware.

Enabling root SSH login on an ESX host

Root Account

AhsayOBM requires root account access to the ESXi server to perform backup and restore.

Port Requirement

• For environment with firewall, the vCenter, ESXi servers and Backup Client Computer must be able to communicate with each other.

• Ensure that ports 22, 80, 111, 443 and 902 allow outbound communication on the vCenter and ESXi servers. Refer to the links below for details on port usage:

  • Required ports for vCenter Server Appliance 5.x
  • Required ports for vCenter Server 6.x
  • Port requirements for ESXi

  Ports 443 and 902 are default ports for VMware.

  If these have been changed from the default in your VMware environment, the firewall requirements will change accordingly.

Disk Space Available on Datastore

Sufficient disk space must be allocated on the datastore (e.g. 1.2 x size of the largest virtual machine selected for backup), where the virtual machine(s) for backup are located.

VMware Tools

VMware Tools are used to quiesce VMs prior to backing them up. To create consistent backup for your VMs on Windows platforms, ensure that VMware Tools are installed, and up to date on all VMs to be backup.

ESXi Hosts and Virtual Machine Hardware Versions Compatibility

Refer to the link below for information on the supported and compatible virtual machine hardware versions in VMware vSphere.

ESXi hosts and compatible virtual machine hardware versions list

Backup Client Computer Requirements

In the following VMware setup:

• Standalone VMware ESXi Server
• VMware vCenter Server
  • Windows VMware vCenter Server
  • VMware vCenter Server Appliance (vCSA)

For backup of virtual machines on VMware vCenter/ESXi Server, it is recommended a separate Backup Client Computer (staging machine) must be prepared for AhsayOBM to be installed on.

AhsayOBM installed on a Windows machine will allow support for VDDK backup mode, Run Direct, Granular Restore and vSAN Cluster.

However, for Standalone VMware ESXi Server and VMware vCenter Server Appliance (vCSA), AhsayOBM can be installed on either a Linux (GUI) or MacOS machine but VDDK backup mode, Run Direct, Granular Restore and vSAN Cluster are not supported on these platforms.

AhsayOBM is installed on a remote backup machine which connects to the standalone VMware ESXi server. The backup is saved either on AhsayCBS, a local destination on the AhsayOBM remote backup machine or to a cloud destination.

For environments with the following vSAN setups, the AhsayOBM setup and deployment for Two Node and Standard vSAN Cluster are similar as they both are on one site.

• Two Node vSAN Cluster
• Standard vSAN Cluster
• Stretched vSAN Cluster

The following are the different types of setups for each vSAN Cluster:

Two Node vSAN Cluster

For environment with Windows vCenter Server with Two Node vSAN Cluster setup, a separate Backup Client Computer must be prepared for AhsayOBM to be installed on.

For VMware vCenter Server Appliance (vCSA) with Two Node vSAN Cluster setup, a separate Backup Client Computer must be prepared for AhsayOBM to be installed on.

Standard vSAN Cluster

For environment with Windows vCenter Server with Standard vSAN Cluster setup, a separate Backup Client Computer must be prepared for AhsayOBM to be installed on.

For VMware vCenter Server Appliance (vCSA) with Standard vSAN Cluster setup, a separate Backup Client Computer must be prepared for AhsayOBM to be installed on.

Stretched vSAN Cluster

For environment with Windows vCenter Server with Stretched vSAN Cluster setup, a separate Backup Client Computer on a third location connected to the production site using internet connection must be prepared for AhsayOBM to be installed on.

For VMware vCenter Server Appliance (vCSA) with Stretched vSAN Cluster setup, a separate Backup Client Computer on a third location connected to the production site using internet connection must be prepared for AhsayOBM to be installed on.

Hardware and Software Requirements

Ensure that the Hardware and Software Requirements as seen in the Download & Installation section are met by the Backup Client Computer or the vCenter computer.

Add-on Module Requirement

Make sure that the VMware VM backup add-on module is enabled for your AhsayOBM user account, and that sufficient number of guest VM / socket license is assigned.

There are two (2) types of license models that you can choose from:

• Per Guest VM license
  • VMware ESXi Standalone - calculated by the total number of guest VMs to back up.
  • VMware vCenter - calculated by the total number of guest VMs to back up.
• Per Socket license
  • VMware ESXi Standalone - calculated based on the total number of physical CPU or sockets for the ESXi machine
  • VMware vCenter - calculated based on the total number of physical CPU or sockets for all VMware ESXi machines under the vCenter environment

To decide which license model is best for you, you must determine the total number of VMs and/or physical CPU that you will be using. Consider the following scenarios:

• You have 1 physical CPU in the ESXi machine with 20 VMs. In this scenario, it would be best to use the per socket license since you will only need 1 license for the physical CPU versus the 20 licenses if you will use the per guest VM license.
• You have 10 physical CPUs under a vCenter environment but only have 5 VMs running. In this case, a per guest VM license would be better than the per socket license.

It depends on the situation that will determine which license model is best to use. Keep in mind to also include your future plans regarding your VMware backup when deciding about which license to use. Contact your backup service provider for more details.

Backup Quota Requirement

Make sure that your AhsayOBM user account has sufficient quota assigned to accommodate the storage for the guest virtual machines. Contact your backup service provider for details.

Port Requirement

• For environment with firewall, the vCenter, ESXi hosts, and Backup Client Computer must be able to communicate with each other.

• Make sure that ports 22, 80, 111, 443 and 902 allow outbound communication on the Backup Client Computer. Refer to the links below for details on port usage:

  • Required ports for vCenter Server 6.x
  • Port requirements for ESXi

  Ports 443 and 902 are default ports for VMware

  If these have been changed from the default in your VMware environment, the firewall requirements will change accordingly.

Backup Client Computer on Linux

For Backup Client Computer running on Linux operating system platform, the Graphical User Interface (GUI) environment (e.g. GNOME or KDE) must be installed to support selection of guest VMs in backup source.

Disk Space Available on Backup Client Computer (or the vCenter Computer)

Sufficient disk space must be allocated on the Backup Client Computer (or the Windows vCenter server if AhsayOBM is installed on this machine) for the temporary directory configured for the backup set, and the formula for the calculation of disk space is as follows:

(Total File Size * Delta Ratio) * number of backup destinations = Maximum Free Space Required

Windows OS Requirement for VDDK Mode

Make sure AhsayOBM is installed on:

• 64-bit Windows OS if you will back up VM data from VMware vCenter/ESXi 6.5 or above.
• For VMware vCenter/ESXi 7 or above, AhsayOBM must be installed on Windows version: Windows 2012 / Windows 2012 R2 / Windows 2016 (including versions 1709 and 1803) / Windows 2019.

Run Direct Requirements

Run Direct is a feature that helps reduce disruption and downtime of your production VMs.

For more details on Run Direct, refer to Instant VM Restore with Run Direct in the Introduction.

To utilize the Run Direct feature, ensure that the following requirements are met:

VDDK Backup Mode

Run Direct restore is only supported for virtual machines that are backed up in VDDK mode. Make sure that the VDDK Backup Mode Requirements are met.

Backup Destination Requirements

• When a Run Direct restore is performed, the backup destination containing the guest VM files is mounted on the VMware host as NFS datastore.
• Ensure that the following requirements are met by the backup destination of the VMware VM backup set:
  • Destination must be accessible to the VMware host.
  • Destination must have sufficient disk space available for the Run Direct restore. There should be 1.5 x total provisioned size of all VMs selected for backup.
  • For Run Direct restore of 1 VM with provisioned size of 100GB, there should be 150GB (e.g. 1.5 x 100GB) of free space available in the Destination.
• Operation System of the Backup Client Computer
  • Run Direct restore is only supported by AhsayOBM installation on Windows.
  • To utilize the Run Direct feature, make sure that AhsayOBM is installed on a supported Windows platform.
• Restore to Alternate Location

  • When performing a Run Direct restore to Alternate Location, only one VM can be selected per restore session.

    

    

  • Consider creating a separate VMware VM backup set for each VM that you intend to perform Run Direct restore (e.g. VMs that you may restore to alternate location).

VDDK Backup Mode Requirements

AhsayOBM supports VDDK backup mode (Virtual Disk Development Kit) for ESXi and vCenter setup. The backup speed is enhanced as the generation of the delta file of the VM are performed directly by the ESXi or vCenter itself. With VDDK backup mode, the following are supported:

• Backup / restore of the resource pool and 'roles' settings, and support of restoration to another name or alternate location on the ESXi platform.
• VM hardware version upgrade, change tracking option and change tracking data option when a new backup set is created.
• Add or remove VM hard disk without uploading the existing hard disk again on the vCenter backup.

For VDDK backup mode, AhsayOBM must be installed on a supported Windows operating system as VDDK backup mode is only supported on Windows platform.

License Requirement

• The VMware vSphere Storage APIs, which are essential for VDDK backup mode, are included with the VMware vSphere Enterprise Standard, Enterprise and Enterprise Plus Edition.
• Ensure that the license requirement is met.

Changed Block Tracking (CBT) on VMs

CBT must be enabled for the VM to be backed up in VDDK mode. Make sure that the following requirements are met:

• The VM must be hardware version 7 or later.
• The VM must have zero (0) snapshots when CBT is enabled.
• The virtual disk must be located on a vSAN volume, VMFS volume backed by SAN, iSCSI, local disk, or an NFS volume.

VMware CBT Known Issues

Although AhsayOBM v8.3.4.0 or above no longer supports the creation of new VMware backup set for VMware vCenter/ESXi v5.0 and v5.1, backup sets which are upgraded from the previous AhsayOBM versions can continue to run with applicable fix.

For VMware vCenter/ESXi v5.0, v5.1, v5.5 and v6.0, there is a known Changed Block Tracking (CBT) bug which can sometimes return incorrect changed sectors on a guest VM. As the CBT is used by the AhsayOBM for VDDK backup modes, it affects the integrity of both incremental and differential backups.

If a VMware backup is performed on any of the affected versions (i.e. v5.0, v5.1, v5.5, and v6.0), even if it was upgraded to a later version, it will be impossible for the AhsayOBM to restore the guest VMs due to the CBT bug, even though all backup jobs are recorded as successful by the AhsayOBM.

As part of the backup job, AhsayOBM will automatically check if the VMware version is affected by the VMware CBT bug. If the problematic VMware version detected is related to the affected version (i.e. v5.0, v5.1, v5.5 and v6.0), then the AhsayOBM will show a warning in the backup report indicating that the VMware host is affected by the CBT bug:

Current backup source includes ESXi server(s) which could sometimes return
incorrect changed sectors (KB2090639).
Please upgrade the following ESXi server(s) to the fixed build to avoid
backup incorrect backup data: [Name:localhost.localdomain (VMware ESXi
5.1.0 build-1157734), FixedBuildNo:2323236]. Reference: VMware ESXi 5.0.x,
5.1.x and 5.5.x (https://kb.vmware.com/s/article/2090639) and VMware ESXi
6.0.x (https://kb.vmware.com/s/article/2136854)

To resolve this problem, it is strongly recommended to perform the following steps:

1. Apply the VMware patch or upgrade the VMware vCenter/ESXi.
2. Perform a full backup of the affected guest VMs.

VMware Snapshot

VDDK backup mode does not support backup of virtual machine snapshot.

For backup of individual virtual disk, the restored virtual machine does not support the reversion of previous snapshots, if the snapshot contains disks which are not previously backed up by AhsayOBM.

Virtual Machine State

VDDK backup mode does not support backup of virtual machine state (e.g. power on state/suspend state).

File Name Requirement

If the file name of the virtual machine contains the following special characters, the https access to the virtual machine’s files will fail:

` ^ ~ = ; ! / ( [ ] { } @ $ \ & # % +

This is due to the percent-encoding specified in the URL standard is not supported for ESXi based HTTP(S) file access. To resolve the issue, please rename the corresponding file to avoid special characters. For instructions on renaming a virtual machine, please refer to the following knowledge base article from VMware: Unable to see files while browsing daastore in Virtual Center.

Restore Requirement

For VMware ESXi restore, the virtual machine must be restored to a VMware ESXi host with the same VMFS datastore version.

For example, the backup of the virtual machine was done on a VMware ESXi host with a VMFS5 datastore in VDDK backup mode but is restored to a VMware ESXi host using a VMFS6 datastore and vice versa.

vSAN Backup and Restore

Requirements

For VMs using vSAN datastore, here are the requirements:

• Supported vSAN setups for AhsayOBM v8.5.0.118 or above.
  • Two Node vSAN Cluster
  • Standard vSAN Cluster
  • Stretched vSAN Cluster

• VMware vSAN version with corresponding vCenter and ESXi compatible version.

  vSAN version	vCenter version	ESXi version
  5.5	5.5 or later	5.5 or later
  6.0	6.0 or later	6.0 or later
  6.1	6.0 or later	6.0 or later
  6.2	6.0 or later	6.0 or later
  6.5	6.5 or later	6.5 or later
  6.6	6.5 or later	6.5 or later
  6.6.1	6.5 or later	6.5 or later
  6.7	6.7 or later	6.7 or later
  7.0	7.0 or later	7.0 or later

• AhsayOBM must be installed on a supported Windows operating system as vSAN backup and restore is only supported on Windows platform.

  Refer to the following article for the list of the supported Windows operating system:

  FAQ: Ahsay Software Compatibility List (SCL) for version 9.1 or above

• Backup set version must be VMware vCenter.

  

• Only VDDK backup mode is supported for VMs in vSAN datastore.
• VMware vMotion must be enabled on the vCenter and ESXi servers for Run Direct to support live migration.
• For Stretched vSAN Cluster, the AhsayOBM staging machine must be located on another site aside from the VMware Center production and backup sites.

Limitations

• Backup and restore of guest VMs on a Stretched vSAN Cluster will be slower since it will be dependent on the internet connection between the AhsayOBM staging machine and the VMware vCenter server compared with a non-Stretched vSAN Cluster backup and restore which is using a LAN connection.

• Run Direct restore may not be possible for Stretched vSAN Cluster since AhsayOBM is located on another site.

  The VMware vCenter server will have to power on and manage the VM, which is stored on a backup destination on the AhsayOBM staging machine through an internet connection.