Creating an Incremental Backup

The following instructions describe how to create an incremental backup by using the send/receive feature. Note that before creating an incremental backup, you must first create a reference backup. See Creating a Reference Backup in Preparation for Creating an Incremental Backup.

To create an incremental backup:

Create a snapshot of the subvolume.

sudo btrfs subvolume snapshot -r /vol /vol/backup_1

Ensure that the snapshot has been written to disk by running the sync command.
```
sudo sync
```
Send only the differences between the reference backup and the new backup to the backup area.
For example:, run
```
sudo btrfs send -p /vol/backup_0 /vol/backup_1 | btrfs receive /backupvol
```
Running the previous command creates the /backupvol/backup_1 subvolume.