Incremental backup Linux command

Depending on what you need from your backups, rdiff-backup may be what you want. It's based on the same idea as rsync, but also keeps historical backups (in a space-efficient manner, by storing the differences).

Dirvish makes incremental snapshots (that look as full directories trees, thanks to the magic of hardlinks), using rysnc under the hood. It works well for me.

rsync is what you are looking for. Here is a nice tutorial.

Here's the command I use for incremental backups of my virtual machine using rsync.

rsync -avh --delete --progress --link-dest="/Volumes/canteloup/vm_backups/`ls -1tr /Volumes/canteloup/vm_backups/ | tail -1`" "/Users/julian/Documents/Parallels" "/Volumes/canteloup/vm_backups/`date +%Y-%m-%d-%H-%M-%S`"

-avh means make an archive, with verbose output in a human readable form.

--delete will make sure each incremental backup does not contain files that have been deleted since the last backup. It means the backup taken on a particular date will be a snapshot of the directory as it was on that date.

--progress will display in the terminal the amount transferred, the percentage, and the time remaining for each file. Handy for virtual machine backups with 40Gb+ file sizes.

--link-dest specifies the directory to use for making links for the files that haven't changed. It uses ls -rt | tail -1 to get the last file. Seems to be fine if the file doesn't exist, as in the first time it is run.

The next arg is the directory to backup.

The last arg is the target directory. The name is a timestamp.