Windows Hot Bare Metal Disaster Recovery


Hot Bare Metal for Windows will allow capturing a Bare Metal image of the client while the client is up and running.



Windows Imaged-based Hot Bare Metal Disaster Recovery


Hot Bare Metal for Windows is available for servers running Microsoft Windows 2000 or higher. Hot Bare Metal will allow capturing a Bare Metal image of the client while the client is up and running. This eliminates the need for downtime when performing a Bare Metal backup.

Note:  This article discusses Windows image-based bare metal protection.  For details about Windows integrated bare metal recovery, another form of hot bare metal protection introduced in the 7.4 release, see Windows integrated bare metal recovery in the Unitrends Administrator's Guide.  With integrated bare metal recovery, you can recover a client from a file-level backup using an ISO provided on the Unitrends appliance.  This eliminates the need to run bare metal backups and create ISO images for the clients you wish to protect. 


There are several fundamental things to understand about Hot Bare Metal before getting started:


Hot Bare Metal is available only for computers running Windows 2000 or higher. The most current Windows client can be downloaded from the Unitrends Customer Care Center at


By default, the Hot Bare Metal backup will capture the boot and system volume of the client machines root disk. The partition containing startup files (ex. NTLDR) is the boot volume and the partition containing the operating system files is the system volume. In most cases they are the same (ex. C:). Root disk is defined as the hard disk that is critical for booting the system. If there are two volumes (ex. C: and D:) on the root disk, and if the second is a data partition, then the backup will automatically exclude this partition from the backup.


Note: Versions of Bare Metal prior to 2.1 enabled the backup of all volumes on the root disk by default. Because it was interactive, it allowed for exclusion of undesirable volumes. Hot Bare Metal, by default, only backs up the boot and system volumes (normally the same). If the user wants to backup all volumes of the root disk on the system, the following fields should be set in the master.ini file on the client (the master.ini file is located on the client in the C:\pcbp directory):




If this section does not exist, create it in the master.ini.


By default, Hot Bare Metal backs up the hard drive on which the user is booted. If multiple hard drives are available and one other than the boot disk needs to be backed up, override the default by editing this setting in the clients master.ini:


RootDisk={disk number}

Hot Bare Metal backups will not include dynamic disks. The configuration for dynamic disks is not within the clients partition boundaries and is therefore not included during the Hot Bare Metal backup.

Registering the client for Hot Bare Metal Backup

The client must be registered on the. This can be done through the user interface (RRC) under Configure>Clients tab. See the section on Client Registrationfor additional instructions.

Hot Bare Metal Backup Schedule

Windows clients can be added to a Hot Bare Metal schedule in the manner described in the Backups and Schedules section. Do not use selection lists for Bare Metal backups. Client option lists can be used to designate a disk device. The Verify operation is not supported for Hot Bare Metal backups.


IMPORTANT: Do not use selection lists for Bare Metal backups.


If using retention levels for Bare Metal backups that differ from other backups, Bare Metal backups must be directed to a unique D2D device. A Hot Bare Metal backup can be scheduled for clients running Windows 2000 operating system or higher.


If any of the following conditions on the client machine are not met, the Hot Bare Metal option will not be available:


Client operating system is not Windows 2000 or higher.

Client Bare Metal software is not version 2.1 or higher.

Client is not registered.


For Vista, Windows 7, Windows 2008 and Windows 2008 R2 clients, run the following commands from the command line before performing a Bare Metal backup:

BCDEDIT /set {bootmgr} device partition=C

BCDEDIT /set {default} device partition=C

BCDEDIT /set {default} osdevice partition=C

Or (if your OS is on the D: partition)

BCDEDIT /set {bootmgr} device partition=C

BCDEDIT /set {default} device partition=D

BCDEDIT /set {default} osdevice partition=D

Testing the Hot Bare Metal boot media

Validating the Hot Bare Metal media is strongly recommended. Perform the following steps to test the media:


Create the Bare Metal boot media for the client

Boot the client machine with the boot media.

Select Utilities > Advanced Settings > Confirm Hardware Detection.


This menu choice will display all of the hard drives detected on the system and the network interfaces. It performs a quick test to confirm that the hardware is correctly detected on the system. This procedure requires a short period of downtime for the client. After the test is completed, the system can be rebooted into normal production mode.


Once the boot media has been validated, it should be safely stored for use during a restore. This procedure ensures that when the restore needs to be performed, the hardware is appropriately detected and the restore completes successfully. If the boot media test is not performed, a message indicating that the Bare Metal boot media has not been tested will be displayed.


Overriding clients should be done only when testing of boot media cannot be completed. Unitrends does not guarantee restore of untested clients. On the other hand, if one hardware platform has been tested, it can be assumed, that all other clients with an identical hardware configuration, would pass a test of the boot media. These duplicate systems are not usually tested.

Best Practices and Product Restrictions for Windows Hot Bare Metal

Microsoft dynamic disks and dynamic volumes are not supported by Hot Bare Metal.


On Windows 2000, Hot Bare Metal does not guarantee application consistency since no applications are compliant with Microsoft Volume Shadow-copy Services (VSS) application programming interfaces on these operating systems.


Applications with databases such as Exchange, SQL Server, etc. (which write to the boot volume) should be stopped for the duration of the Hot Bare Metal backup.


Due to limited VSS support in Windows 2000, combinations of non-VSS aware applications can result in consistency issues with the system state. This can cause Bare Metal images to be unstable. When this occurs, users can use the traditional Bare Metal process to insure Bare Metal image integrity, or plan to upgrade to Windows 2003 or later.


It is advised to refrain from defragmenting volumes that have snapshots on them as this possibly can lead to the exhaustion of the snapshot cache file, resulting in inconsistent snapshots.


Ensure that the latest service packs are installed on the Windows systems.

Do not use any other snapshot products simultaneously with the appliance protection software as this can result in the snapshot being inconsistent.


IMPORTANT: A Bare Metal backup cannot be restored to a smaller disk.






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