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Full server migration requirements

After you have verified your source server meets the Requirements, verify that your target server meets the requirements below for full server migration.

Keep in mind that an existing physical or virtual target server may meet these requirements but may not be suitable to stand-in for a source in the event of a source failure. See the table Target compatibility for additional information regarding an appropriate target server for your particular source.

• Operating system—Your existing physical or virtual target server can have any of the following Windows operating system editions.

• Windows Server 2008 or 2008 R2 Datacenter, Enterprise (i386, x64), Standard (i386, x64), Essential Business Server, Web Server, Foundation Server, Small Business Server, or Storage Server Edition

• Windows Server 2003 or 2003 R2 Datacenter, Enterprise (i386, x64), Standard (i386, x64), Web Server, Small Business Server, or Storage Server Edition. Each of the Windows 2003 operating systems require Service Pack 1 or later.

• Hyper-V servers—Full server migration of a Hyper-V server is not supported.

• 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 needed for the Double-Take program files. For Windows 2003, this is approximately 300 MB. For Windows 2008, this is approximately 375 MB.

  The program files can be installed to any volume while the Microsoft Windows Installer files are automatically installed to the operating system boot volume.

  Make sure you have additional disk space for Double-Take queuing, logging, and so on.

   

• Disk space for data files—This is the amount of disk space needed for the source data files. This will be dependent on the applications you are running and the amount of data files you have.

• Disk space for system state image—This is the amount of disk space for 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 includes Unicode file system support, but your server name must still 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.

• Protocols and networking—Your servers must meet the following protocol and networking requirements.

  • Your servers must have TCP/IP with static IP addressing. (Some job types allow you to add DHCP addresses for failover monitoring, although only after a job has already been created. Keep in mind that depending on your failover configuration, a source reboot may or may not cause a failover but having a new address assigned by DHCP may also cause a failover.)
  • By default, Double-Take 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 Server and job settings for details.
  • 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. 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 CD, via a web connection during the Double-Take installation, or from a copy you have obtained manually from the Microsoft web site.

• Cloud—Double-Take can be used to migrate a server to an existing server in the cloud. Keep in mind that you should enable appropriate security measures, like VPN, to protect your data as it migrates to the cloud.

• Supported configurations—The following table identifies the supported configurations for a full server migration job.

  Configuration		Supported	Not Supported
  Source to target configuration	One-to-one, active/standby	X
  	One-to-one, active/active		X
  	Many-to-one		X
  	One-to-many		X
  	Chained		X
  	Single server		X
  Server configuration	Standalone-to-standalone	X
  	Standalone-to-cluster		X
  	Cluster-to-standalone		X
  	Cluster-to-cluster		X
  	Cluster Shared Volumes (CSV) guest level	X
  	Cluster Shared Volumes (CSV) host level		X
  Upgrade configuration	Upgrade 5.2 Double-Take Move Console server migration job to 6.0 Double-Take Console full server migration job		X
  	Upgrade 5.3 Double-Take Move Console server migration job to 6.0 Double-Take Console full server migration job		X

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 cutover occurs.

  If your source is a domain controller, it will start in a non-authoritative restore mode after cutover. This means that if the source was communicating with other domain controllers before cutover, it will require one of those domain controllers to be reachable after cutover so it can request updates. If this communication is not available, the domain controller will not function after cutover. 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 cutover 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 cutover.
• 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 cutover.
• Network adapters—You must map at least one NIC from the source to one NIC on the target. If you have NICs on the source that are not being used, it is best to disable them. 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 cutover. If there are more NICs on the target than the source, the additional NICs will still be available after cutoverand will retain their pre-cutovernetwork settings.
• File system format—The source and the target must have the same NTFS file system format on each server. FAT and FAT32 are no longer supported.
• 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:. Additional target volumes are preserved and available after cutover, with all data still accessible.
• 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.

• 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, installed applications, and user data will increase the disk space requirement.

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