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Product Version: 7.3
Last Modified: 23 Nov 2017

Questions

I use the forever incremental backup repository.
After opening the folder where my backup repository is located I can see there are several folders and many files, but I cannot find individual backups.

  • What is the format used to store my backups?
  • Where is my incremental file chain?
  • Can I find a particular backup in the backup repository folder?
  • Can I extract a single backup from the backup repository manually?

Answer

Forever incremental backup repository uses the proprietary format for storing block-level data.
All blocks are spanned across multiple files. If deduplication is enabled, one block may belong to multiple objects. 
A single backup cannot be found in the backup repository by name or extracted manually.

Backups in such backup repository are forever incremental. After the first full backup, all consequent backups accumulate the changed data; periodic full backup is not required. The solution uses synthetic mode to store backup data: after each backup, it creates a recovery point, which references all blocks required to reconstruct the VM (instance) as of this recovery point.

If the amount of changes in a 100 GB VM is just 500 MB, only 500 MB of new data will be added to the Backup Repository. 
However, the new recovery point will reference the complete set of blocks which are required to restore the entire VM as of this recovery point.

Here is a simplified example of a forever incremental backup repository. 
Let’s say backup for a certain VM runs every day. For the sake of simplicity, we will assume that the VM initially has only of 2 data blocks: A and B.

  1. The first (full) backup runs on Sunday. Blocks A and B are backed up.
  2. On Monday, incremental backup finds that the block A is removed from the VM, while a new block C is added to the VM. Block C is backed up.
  3. On Tuesday, incremental backup finds that the block B is removed from the VM, while a new block D is added to the VM. Block D is backed up.

Here is how the original VM would actually look like on each of the three days:

Original VM

And here is how the recovery points of this VM would be stored in the Backup Repository:

VM recovery points

If you delete the Monday recovery point via NAKIVO Backup & Replication interface, no data blocks will be removed from the Backup Repository, as blocks B and C are also referenced by Sunday and Tuesday.

NOTE: All data blocks are stored in the files under “raw” folder inside “NakivoBackup” folder. 
The blocks inside each file may belong to multiple VMs and recovery points. 
Information about backups and their recovery points is stored in folders named after UUID of each backup. 
Global metadata of the Backup Repository is stored inside “.desc” and “.desc2” files.

IMPORTANT: Do not modify or delete any files inside the “NakivoBackup” folder.
Modifying or deleting any file of the Backup Repository may damage your backups.

 



 

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