Is there an rsync alternative, that stores compressed and encrypted?

Question

I'm looking for a suitable off-site backup / file synchronization solution. Both local client and remote server run linux. Storage space on the server is limited, bandwidth between client and server is very limited.

I had a look at duplicity, Back In Time, Déjà Dup, luckyBackup, rsnapshot, rdiff-backup, rsynccrypto. None of those seem to do what I want, at least if I understand them correctly. They either store multiple versions, or do a full retransmit each time, or lack encryption, or lack compression. I tried a rsync/fusecompress/encfs combination, but fusecompress keeps destroying my files. I searched superuser and askubuntu, found only one similar question here (How to do rsync-like encrypted backup?), but there is no talk about compression and no fitting solution either.

Requirements:

• simple mirroring, only one copy of the files (limited storage space)
• update only the files that changed since last sync (limited bandwidth)
• store files compressed and encrypted
• encryption should happen on the client before transmitting

Basically, what I want is something that behaves like rsync, but stores the mirrored files compressed and encrypted. Does something like that exist?

Solution 1

If server is running ssh:

1. mount remote site locally with

   sshfs -o nonempty,sshfs_sync,compression=yes username@host:/path/archives/ /mounted/encrypted/
   

2. Create the encrypted system and mount it (The first time you try to mount the directory, encfs will create the encrypted filesystem. It works like the regular mount):

   encfs /mounted/encrypted /mounted/unencrypted 
   

3. use rsync to /mounted/unencrypted

4. unmount encryption

   fusermount -u /mounted/unencrypted
   

5. eventually unmount remote resource

   umount /mounted/encrypted
   

Solution 2

@Alfred Rupp,

Have you checked "Areca Backup"?

I think it fills the bill on everything you are asking/needing.

http://areca-backup.org/

Comments

[CharlieRB]

This is not meant to be mean but may sound like it; it appears like you are placing an order. We are here to help you, not do it for you. What have YOU searched/found/tried so far?

[Alfred Rupp]

@CharlieRB I had a look at duplicity, Back In Time, Déjà Dup, luckyBackup, rsnapshot, rdiff-backup, rsynccrypto. None of those seem to do what I want, at least if I understand them correctly. They either store multiple versions, or do a full retransmit each time, or lack encryption, or lack compression. I tried a rsync/fusecompress/encfs combination, but fusecompress keeps destroying my files. I searched superuser and askubuntu, found only one similar question here (How to do rsync-like encrypted backup?), but there is no talk about compression and no fitting solution either.

[CharlieRB]

Great. That is the detail needed in your question. I added it for you so everyone who reads your question knows what you've tried and won't offer the same solutions.

[HikeMike]

You want to compress (server-side) client-side encrypted files? How do you think this'll work?

[Alfred Rupp]

@Daniel Beck: I want to compress client-side, then encrypt client-side, then transmit.

[HikeMike]

If you're willing to let someone else host it, tarsnap might work for you.

[Alfred Rupp]

This is, what I've been doing so far, but it lacks compression. I can add a gzip -r, but then sshfs is not an option anymore, and I have to rsync twice. (rsync to a temporary dir, gzip -r that dir, rsync to the server)

[jet]

so then between 1) and 2) mount FuseCompress file system: code.google.com/p/fusecompress

[ʀᴏʙ]

@jet between 1) and 2) is encrypted data; it's highly random and not likely to compress.