You are here: Double-Take RecoverNow requirements > Recovery server requirements

Recovery server requirements

This is the server that will become your new source when you are recovering an entire server. This server can be an existing physical or virtual machine, or Double-Take RecoverNow can provision (automatically create) a virtual machine for you during the recovery process.

Operating system—You have several options for your recovery server operating system.

Physical or existing virtual machine—If your recovery server is a physical server or an existing virtual server, it can have any of the following Windows operating system editions.
- Windows Server 2008 or 2008 R2 Enterprise (x86, x64), Standard (x86, x64), Web Server.
- Windows Server 2003 or 2003 R2 Enterprise (x86, x64), Standard (x86, x64), Web Server. Each of the Windows 2003 operating systems require Service Pack 1 or later.
Keep in mind that a physical or existing virtual recovery server may meet these requirements but may not be suitable to recover the source in the event of a source failure. See the Target compatibility table for additional information regarding an appropriate recovery server for your particular source.
Provisioned virtual machine on Hyper-V—If your recovery server will be provisioned (automatically created during the recovery process), you must have a physical Hyper-V host machine where Double-Take RecoverNow can create the new virtual server. Provisioning a virtual machine on Hyper-V also includes the following requirements.

Your physical Hyper-V host machine can be any Windows 2008 or 2008 R2 operating system from the supported source server operating systems that has the Hyper-V role enabled. In addition, you can use Hyper-V Server 2008 R2 or Server Core 2008 R2 with the Hyper-V role enabled. (Hyper-V Server 2008 and Server Core 2008 are not supported.)
If you are using Hyper-V Integration Services and your source is running Windows 2003, the source must have Service Pack 2 or later.
The virtual machines cannot use raw, pass-through, or differencing disks.
Your repository server cannot be a physical or virtual machine on the same Hyper-V host where you want to provision a new virtual machine.

Provisioned virtual machine on ESX—If your recovery server will be provisioned (automatically created during the recovery process), you must have a physical ESX host machine where Double-Take RecoverNow can create the new virtual server. Provisioning a virtual machine on ESX also includes the following requirements. Note that ESX is commonly referred to as the Classic edition and ESXi as the Embedded and Installable edition.

ESX 3.5.x or ESXi 3.5.x Standard, Advanced, Enterprise, or Enterprise Plus
ESX 4.0.x or 4.1 or ESXi 4.0.x or 4.1 Standard, Advanced, Enterprise, or Enterprise Plus

If you are using the Standard edition of ESX 4.0 or ESXi 4.0, you must have update 1 or later.

If your source is a Windows 2008 R2 server, your ESX server must have version 3.5 update 5 or later or ESX 4.0 update 1 or later.
Your repository server cannot be a virtual machine on the same ESX host where you want to provision a new virtual machine.
Virtual recovery appliance—The ESX server must have an existing virtual machine, known as a virtual recovery appliance, that meets the following requirements. (When you are ready for recovery, the virtual recovery appliance will create a new virtual server, mount disks, format disks, and so on. Then the new virtual machine is detached from the virtual recovery appliance and powered on. Once the new virtual machine is online, it will have the identity, data, and system state of the original source. Since the virtual recovery appliance maintains its own identity, it can be reused for additional recoveries.)

The virtual recovery appliance must be running Windows Server 2008, 2008 R2, 2003, or 2003 R2.
The virtual recovery appliance must have the same or newer operating system than the source (not including service pack level).
The virtual recovery appliance must have Double-Take RecoverNow installed and licensed on it.

System memory—The minimum system memory on each server should be 1 GB. The recommended amount for each server is 2 GB.
Disk space for program files—This is the amount of disk space, approximately 130 MB, needed on the repository server to hold the Double-Take RecoverNow program files.
Disk space for data files—This is the amount of disk space on the repository server to hold all of the source data files. This will be dependent on the number of sources you are protecting, the applications you are running on each source, and the amount of data files on each source.
Disk space for system state image—If you are protecting an entire server, this is the amount of disk space on the repository server to hold the image of the source system state. The size of the system state will depend on the operating system and architecture. Windows 2003 operating systems need at a minimum 2-3 GB of free space for the system state. Windows 2008 operating systems need at a minimum 7-9 GB of free space for the system state. Windows 2008 R2 operating systems need 10 GB of free space for the system state. These minimums are for a clean operating system installation. Operating system customizations will increase the disk space requirement.
Server name—Double-Take RecoverNow includes Unicode file system support, but your server name must be in ASCII format. If you have the need to use a server's fully-qualified domain name, your server cannot start with a numeric character because that will be interpreted as an IP address.
Network protocols—Your servers must meet the following protocol and networking requirements.

Your servers must have TCP/IP with static IP addressing.
By default, Double-Take RecoverNow is configured for IPv6 and IPv4 environments, but the Double-Take service will automatically check the server at service startup and modify the appropriate setting if the server is only configured for IPv4. If you later add IPv6, you will need to manually modify the DefaultProtocol server setting. See the Double-Take Availability Scripting Guide for details on modifying that server setting.
IPv6 is only supported for Windows 2008 servers.
If you are using IPv6 on your servers, your clients must be run from an IPv6 capable machine.
In order to properly resolve IPv6 addresses to a hostname, a reverse lookup entry should be made in DNS.

Microsoft .NET Framework—Microsoft .NET Framework version 3.5 Service Pack 1 is required on the source. This version is not included in the .NET version 4.0 release. Therefore, even if you have .NET version 4.0 installed, you will also need version 3.5.1. You can install this version from the Double-Take RecoverNow CD, via a web connection during the Double-Take RecoverNow installation, or from a copy you have obtained manually from the Microsoft web site.

Target compatibility

Operating system version

The source and target must have the same operating system. For example, you cannot have Windows 2003 on the source and Windows 2008 on the target. The two servers do not have to have the same level of service pack or hotfix. Windows 2003 and 2003 R2 are considered the same operating system, however the Windows 2008 and 2008 R2 releases are considered different operating systems. Therefore, you can have Windows 2003 on the source and Windows 2003 R2 on the target, but you cannot have Windows 2008 on the source and Windows 2008 R2 on the target. The Windows edition (Standard, Enterprise, and so on) does not have to be the same.

Server role

The target cannot be a domain controller. Ideally, the target should not host any functionality (file server, application server, and so on) because the functionality will be removed when recovery occurs.

If your source is a domain controller, it will start in a non-authoritative restore mode after recovery. This means that if the source was communicating with other domain controllers before recovery, it will require one of those domain controllers to be reachable after recovery so it can request updates. If this communication is not available, the domain controller will not function after recovery. If the source is the only domain controller, this is not an issue.

Architecture

The source and the target must have the same architecture. For example, you cannot migrate a 32-bit server to a 64-bit server.

Processors

There are no limits on the number or speed of the processors, but the source and the target should have at least the same number of processors. If the target has fewer processors or slower speeds than the source, there will be performance impacts for the users after recovery.

Memory

The target memory should be within 25% (plus or minus) of the source. If the target has much less memory than the source, there will be performance impacts for the users after recovery.

Network adapters

You must map at least one NIC from the source to one NIC on the target. If the source has more NICs than the target, some of the source NICs will not be mapped to the target. Therefore, the IP addresses associated with those NICs will not be available after recovery. If there are more NICs on the target than the source, the additional NICs will still be available after recovery.

File system format

The source and the target must have the same file system format. For example, an NTFS volume cannot be sent to a FAT volume.

HAL type and version

The Windows hardware abstraction layer (HAL) refers to a layer of software that deals directly with your computer hardware. The HAL type and version do not have to be identical, but they must be compatible between the source and the target. If the two are incompatible, Double-Take Move will warn you. In that case, you must upgrade or downgrade the target.

System volume

The target must have the same system volume as the source. The system volume is the disk volume that contains the hardware-specific files that are needed to start Windows. The system volume might be the same volume as the boot volume, but that configuration is not required.

Logical volumes

There are no limits to the number of logical volumes, although you are bound by operating system limits. For each volume you are protecting on the source, the target must have a matching volume. For example, if you are protecting drives C: and D: on the source, the target cannot have drives D: and E:. In this case, the target must also have drives C: and D:.

System path

The source and the target must have the same system path. The system path includes the location of the Windows files, Program Files, and Documents and Settings.

Double-Take Move path

Double-Take Move must be installed on the same volume on the source and the target.

Disk space

The target must have enough space to store the data from the source. This amount of disk space will depend on the applications and data files you are protecting. The more data you are protecting, the more disk space you will need.

The target must also have enough space to store, process, and apply the source's system state data. The size of the system state will depend on the operating system and architecture. Windows 2003 operating systems need at a minimum 2-3 GB of free space for the system state. Windows 2008 operating systems need at a minimum 7-9 GB of free space for the system state. Windows 2008 R2 operating systems need 10 GB of free space for the system state. These minimums are for a clean operating system installation. Operating system customizations will increase the disk space requirement.