- Overview
- Understanding Consolidation's Impact on Synchronization
- Using RoboCopy to Synchronize Folders
Overview
Where possible, it is recommended that multiple copies of backup files be created to ensure redundancy in the event that a backup becomes corrupted or inaccessible. One backup strategy that recommends this is the 3-2-1 backup strategy.
One way to create multiple copies of backup files is by synchronizing backup files, which creates a copy automatically when a new backup is created.
However, to ensure that backup sets are being synchronized correctly, it is important to consider consolidation rules.
Understanding Consolidation's Impact on Synchronization
When backup sets are consolidated by either creating a synthetic full or merging incremental backups, subsequent incremental backups in the chain are updated to reflect the consolidation. This can be observed by looking at the file modification time stamps in Windows Explorer.
Example 1: Synthetic full, retaining 5 incremental backups
In this example, when the 6th incremental backup is created, the full backup is merged with the first incremental, and existing incremental backups 2 to 5 are updated to indicate that incremental 1 is no longer in the backup chain by modifying the file index. This process is repeated for each subsequent incremental that is run.
Example 2: Incremental merge, retaining 5 incremental backups
In this example, when the 6th incremental backup is created, the first incremental is merged with the second, and existing incremental images 3 - 5 are updated to indicate that incremental 1 is no longer in the backup chain by modifying the file index. This process is repeated for each subsequent incremental that is run.
When creating duplicate copies of backup files, it is essential to synchronize all files in the backup set rather than just copy the most recently created file.
Using Robocopy to Synchronize Folders
Windows includes a file copy utility called 'Robust File Copy' or 'Robocopy'. Robocopy can easily synchronize two folders and ensure that copies are kept up to date.
For example, the following command line will synchronize all Macrium Reflect files in "D:\BackupFolder" with "E:\BackupSyncFolder":
Robocopy "D:\BackupFolder" "E:\BackupSyncFolder" *.mr* /copy:DAT /lev:0 /purge
Macrium Reflect can create VBScript and PowerShell scripts to automatically run Robocopy following the creation of a new backup. This enables backup sets to be easily synchronized to a second location and keep the copy up-to-date with the backup destination. More information about this can be found in the article below: