Duplicati

This review is based on the "experimental" version 2.0.

Duplicati is fantastic software for backing up your files. It works on Mac, Windows and Linux. You select a folder or folders for it to keep and eye on, and corresponding folders where your backed up files should end up. It then asks for a schedule - how often it should look for changes and make a backup. It can listen every six minutes or more. The interface is based in your internet browser, a little bit like SyncThing, but even smoother in the way it works.

Although Duplicati has built in support to talk directly to online Sync/backup services, such as Dropbox, this is a little unnecessary, since you can tell the clients of such services simply to watch out for a particular folder, and you can choose the destination folder discussed above.

More impressive is that Duplicati comes with optional encryption for your files. When choosing the folder the app is watching, you choose also the encryption option and a (hopefully strong) password. With that setup, Duplicati will not only produce a backed up verion of your files, but encrypt them along the way using the very strong AES-256 standard. This way, if the destination folder is being monitored by a backup or sync client (e.g. of Dropbox), only encrypted versions of your files will be put into the cloud. That is very important for maintaining your online privacy, because Dropbox and related services have access to all your files, and have been known to a) get hacked, b) pass on people's info (files included) to law enforcement. Duplicati even hides the size and structure of your files. If you use encryption to backup, say, a 700 Mb file (ahem), the encrypted output from Duplicati will be 14 x 50MB files, which are unreadable to anyone who doesn't have the password. Moreover, to restore a file from backup, you enter the password and it restores the file structure in a menu, so you can pick what you want from all the files you backed up without having to decrypt/restore everything (unless you want to).

The only comparable app to this is Cryptomator, which also encrypts on a file-by-file basis, but is more tuned to syncing than to backups. (Check that out also: it's excellent for protecting your privacy if you're using the Cloud.)

Duplicati is brilliant, and the developer deserves a medal. Or, if you prefer, a donation. It's really a great thing that software this useful is freely available and open source. Highly recommended.

Concerning scheduling, VSS and cleaning up file/folder-backups Duplicati is the best free and portable app for folder-backup-purposes with VSS. For backups of single files I prefer Uranium (portable) or Cobian backup. Uranium Backup has the very important VSS-ability only in the very expensive commercial version, Cobian BU is not portable and is not so good in time-scheduling. But the next Duplicati-version will have a new and better UI, where you can select single files without using regular expressions.
For a good backup functionality it is necessary to cleanup more/older than x backups (CLU) not only older backups than x months, and to configure the schedule of a backup also for each 2nd Monday 10:00 and to pause if the system is busy (Sch).

Comparison of file/folder backup applications:

Comparison ......... CLU . Sch . Language

SyncBack Free...... No ... Yes .. English only

Cobian Backup .... Yes .. No ... Many

Acronis True Im.... Yes .. Yes .. Many

Duplicati ...............Yes .. Yes .. Dan.,En.,Fr.,Germ.,Port.

Areca Backup ..... No .. Yes .. English only

Personal Backup .. No . Yes .. Engl.+German

Saft Backup .........Yes .. No .. Engl.+German

Duplicati is the best free and portable backup application:

Acronis True Image has all necessary functions, has multi-language UI and additionally can do harddisk images with best functions, but it is not free and it is not portable, so you need admin rights to install it.
Both Duplicati and Saft Backup can do backups with Volume Shadow Copy Service (VSS), but Saft Backup cannot do a backup on each second Monday and has no flexible file filter. Cobian Backup is very good, but has the big disadvantage, not to be able to schedule a backup e.g. monthly on each 2nd Tuesday and not to be portable.

This seems very poorly designed.

You can try to backup ~2 TB of data and it says that it needs to backup 600 TB(!), probably from following recursive symlinks or something? There's no obvious way to find out where the links are or how to exclude them.

Or it tells you there's been an error, and when you click "Show" it shows a list of plain text dates that aren't obviously clickable. If you click one, it shows you a dump of json(?) code that means very little. You can search for "error" and try to find the errors that way.

If you've requested a folder to be backed up and the folder is then deleted, Duplicati just stops backing up anything! Your data could very easily be lost.

[Edited by endolith, July 16]

After months of using this, I've lowered my rating to the worst score. It's highly buggy and poorly-written, and there's little helpful support on their forum.

The biggest limitation of Duplicati, as I see it, is that the target of the backup is always a single archive file. Many of the other tools in this space (for example, GFI Backup) can either create a compressed and/or encrypted archive (like Duplicati) OR, a replica of the local file system. This has the merit that tools like GFI Backup can be used for backing up OR for creating and maintaining a mirror.

Oh, and the UI sucks. To run a single back up task once, I have to right click on the system tray icon, then click "wizard", then click "run a backup immediately", then select my backup, then click "next", then click "finish".

That said, the range of places that Duplicati is capable of backing up to is impressive.

• Dave

I use Duplicati 1.3.2.1354 (portable) in German language from [http://code.google.com/p/duplicati/downloads/list](http://code.google.com/p/duplicati/downloads/list "http://code.google.com/p/duplicati/downloads/list") .

The window "Backup storage options" for entering the SkyDrive credentials should be translated to German.
It seems that these strings have been translated already, but are not used in the window in Duplicati 1.3.2.1354.

Some strings in Aug.1th, 2012 are not listed in the translation file and must be added to the translation file report.de-DE (1).

I tested a Duplicati-Backup of a folder with 6.63MB to the in Duplicati created folder Duplicati.BU in my SkyDrive.
To complete the test I restored the files afterwards and tested the integrity. All files are OK. Very perfect!

I know no other backup-app, which is able to do backups to MS Live SkyDrive as Duplicati does.


(1) http://goo.gl/nX2C9

[Edited by em4020, August 01, 2012]