User`s guide

Backup archive components

Archive - Known as archive chain or archive group, it is the whole set of backup files managed by a

single backup task. The archive can consist of one or several slices.

Slice - It is a set of files created during each cycle of the task execution. The amount of slices created

is always equal to the amount of times the task is executed. A slice represents a point in time, to

which the system or data can be recovered.

Volume - It is a tib file associated with the slice. Usually there is only one volume per slice however,

each slice may consist of several volumes. If you have set archive splitting in the task options, the

resulting slice will be split into several files. In addition, Acronis True Image OEM Quick Backup

automatically splits a slice into several files of 4GB each (except the last file) when you make a large

backup to a FAT32 formatted hard disk. These files are the slice's volumes.

Snapshots

While creating disk images, Acronis True Image OEM Quick Backup uses "snapshot" technology that

allows creating even system partition backups while running Windows with files open for reading and

writing without the necessity to reboot the computer. Once the program starts the partition backup

process, it temporarily freezes all the operations on the partition and creates its "snapshot".

Snapshot creation usually takes just several seconds. After that the operating system continues

working as the imaging process is under way and you will not notice anything unusual in the

operating system functionality.

In its turn, the Acronis driver continues working to keep the point-in-time view of the partition.

Whenever the driver sees a write operation directed at the partition, it checks whether these sectors

are already backed up and if they are not, the driver saves the data on the sectors to be overwritten

to a special buffer, then allows overwriting. The program backs up the sectors from the buffer, so

that all the partition sectors of the point-in-time when the snapshot was taken will be backed up

intact and an exact "image" of the partition will be created.

Backup file format

Acronis True Image OEM Quick Backup saves backup data in the proprietary tib format using

compression. This provides for reducing the storage space requirements, as well as for backward

compatibility with the previous Acronis True Image OEM Quick Backup version. While creating a tib

file, the program calculates checksum values for data blocks and adds these values to the data being

backed up. These checksum values allow verifying the backup data integrity. However, using the

proprietary format means that the data from such backups can be recovered only with the help of

Acronis True Image OEM Quick Backup itself – either in Windows or in the recovery environment.

Backup archive validation

How can you be sure that you'll be able to recover your system if the need arises? The feature called

backup validation provides a high degree of such assurance. As was already said, the program adds

checksum values to the data blocks being backed up. During backup validation Acronis True Image

OEM Quick Backup opens the backup file, re-calculates the checksum values and compares those

values with the stored ones. If all compared values match, the backup file is not corrupted and there

is a high probability that the backup can be successfully used for data recovery. It is highly

recommended to validate system partition backups after booting from the rescue media. For users of

Windows 7 Enterprise and Windows 7 Ultimate Acronis True Image OEM Quick Backup provides a

unique way of ensuring that you will be able to boot from the recovered system partition. The

program allows booting from a tib file containing the system partition image, though it first converts