User manual

Table Of Contents

Disk backup (Image)

A backup (p. 258) that contains a sector-based copy of a disk or a volume in a packaged form.

Normally, only sectors that contain data are copied. Acronis Backup provides an option to take a raw

image, that is, copy all the disk sectors, which enables imaging of unsupported file systems.

Disk group

A number of dynamic disks (p. 263) that store the common configuration data in their LDM

databases and therefore can be managed as a whole. Normally, all dynamic disks created within the

same machine (p. 266) are members of the same disk group.

As soon as the first dynamic disk is created by the LDM or another disk management tool, the disk

group name can be found in the registry key

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\dmio\Boot Info\Primary Disk

Group\Name.

The next created or imported disks are added to the same disk group. The group exists until at least

one of its members exists. Once the last dynamic disk is disconnected or converted to basic, the

group is discontinued, though its name is kept in the above registry key. In case a dynamic disk is

created or connected again, a disk group with an incremental name is created.

When moved to another machine, a disk group is considered as ‘foreign’ and cannot be used until

imported into the existing disk group. The import updates the configuration data on both the local

and the foreign disks so that they form a single entity. A foreign group is imported as is (will have the

original name) if no disk group exists on the machine.

For more information about disk groups please refer to the following Microsoft knowledge base

article:

222189 Description of Disk Groups in Windows Disk Management

http://support.microsoft.com/kb/222189/EN-US/

Dynamic disk

A hard disk managed by Logical Disk Manager (LDM) that is available in Windows starting with

Windows 2000. LDM helps flexibly allocate volumes on a storage device for better fault tolerance,

better performance or larger volume size.

A dynamic disk can use either the master boot record (MBR) or GUID partition table (GPT) partition

style. In addition to MBR or GPT, each dynamic disk has a hidden database where the LDM stores the

dynamic volumes' configuration. Each dynamic disk holds the complete information about all

dynamic volumes existing in the disk group which makes for better storage reliability. The database

occupies the last 1MB of an MBR disk. On a GPT disk, Windows creates the dedicated LDM Metadata

partition, taking space from the Microsoft Reserved Partition (MSR.)