rsnapshot to Amazon S3?

Solution 1:

Have you tried, http://duplicity.nongnu.org/ ? It supports a lot of things to backup on including Amazon S3. From the features page,

Currently local file storage, scp/ssh, ftp, rsync, HSI, WebDAV, Tahoe-LAFS, 
and Amazon S3 are supported, and others shouldn't be difficult to add.

rsnapshot isn't an actively developed project any more (last release 1.2.0 was in 2005). Duplicity is actively developed (May 2012 release) and you may want to take a look at that.

UPDATE 1: Duplicity supports full UNIX permissions -- http://duplicity.nongnu.org/duplicity.1.html

Duplicity incrementally backs up files and directory by encrypting tar-format volumes with GnuPG and uploading them to a remote (or local) file server. See URL FORMAT for a list all supported backends and how to address them. Because duplicity uses librsync, the incremental archives are space efficient and only record the parts of files that have changed since the last backup. Currently duplicity supports deleted files, full Unix permissions, uid/gid, directories, symbolic links, fifos, etc., but not hard links.

s3 has object and bucket policies for read/write/update access that you configure for users and groups.

UPDATE 2: rsnapshot has a active github community and releases are frequent https://github.com/rsnapshot/rsnapshot

Solution 2:

For S3 you really want a few big files rather than lots of small files, and so rsnapshot's scheme isn't a great fit for this (at least not for uploading directly). S3 also has no concept of *nix permissions or ownership. You want to find a backup system which creates archive files of some sort -- these store permissions and ownership internally, and create a few big files which can be uploaded to S3 and managed sensibly.