If you get the following errors when trying to extract a tar file:
/bin/tar: Ignoring unknown extended header keyword `SCHILY.dev' /bin/tar: Ignoring unknown extended header keyword `SCHILY.ino' /bin/tar: Ignoring unknown extended header keyword `SCHILY.nlink'
Then you'll likely need to update the version of gnu tar on the box that created the backups, and then create the backups again.
To update your version, you can either use your system's package system (if a new version is avaiable) or else compile the latest on your own, eg:
wget http://files.directadmin.com/services/all/tar-1.20.tar.gz tar xvzf tar-1.20.tar.gz cd tar-1.20 ./configure make mv /bin/tar /bin/tar.old cp src/tar /bin/tar
Note that you can install this on the box that is doing the restore. It will not get rid of the errors completely, but the newer version is better suited to get through them, so you at least have a restored account.