I just tried xtrabackup-2.1.2 and it looks like it does fix the error I had listed. I now have a separate, but I believe to be a related bug. If you'd prefer I can open a new ticket, but in the meantime I'll post it here: I'm using percona-server-5.5 and Ubuntu 12.04 with xtrabackup-2.1.2. If I run xtrabackup --stream=tar ./ > backup.tar, I get the appropriate backup file, with no errors, but if I then pipe that command into gzip like the documentation says I can (and which worked fine in xtrabackup-2.0.7) the backup appears to go on forever and doesn't ever finish: