Acronis Backup for Linux Server - User Guide - Manual (Page 86)

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This option defines whether a file change is detected using the file size and time stamp or by
comparing the file contents to those stored in the archive.
The preset is: Enabled.
Incremental or differential backup captures only data changes. To speed up the backup process, the
program determines whether a file has changed or not by the file size and the date/time when the
file was last modified. Disabling this feature will make the program compare the entire file contents
to those stored in the archive.
4.7.12 File-level backup snapshot
This option is effective only for file-level backup in Windows and Linux operating systems.
This option defines whether to back up files one by one or by taking an instant data snapshot.
Note: Files that are stored on network shares are always backed up one by one.
The preset is: Create snapshot if it is possible.
Select one of the following:

Always create a snapshot
The snapshot enables backing up of all files including files opened for exclusive access. The files
will be backed up at the same point in time. Choose this setting only if these factors are critical,
that is, backing up files without a snapshot does not make sense. To use a snapshot, the backup
plan has to run under the account with the Administrator or Backup Operator privileges. If a
snapshot cannot be taken, the backup will fail.

Create a snapshot if it is possible
Back up files directly if taking a snapshot is not possible.

Do not create a snapshot
Always back up files directly. Administrator or Backup Operator privileges are not required.
Trying to back up files that are opened for exclusive access will result in a read error. Files in the
backup may be not time-consistent.
4.7.13 LVM snapshotting
This option is effective only for Linux operating systems. This option is effective for both disk-level
and file-level backup of volumes managed by Linux Logical Volume Manager (LVM). Such volumes are
also called logical volumes.
This option defines how a snapshot of a logical volume is taken. Acronis Backup can do this on its
own or rely on Linux Logical Volume Manager (LVM). Use of a snapshot ensures a time-consistent
backup of a volume whose data may change during the backup process.
The preset is: Acronis Backup
Select one of the following:

Acronis Backup
Acronis Backup will take the snapshot on its own. With this setting, a backup normally proceeds
faster and unallocated space on the volume group is not required. Therefore, we recommend
changing the preset only if you are experiencing problems with backing up logical volumes.