[CalendarServer-users] off topic: tar --xattr

I'm using calendarserver on Ubuntu Intrepid because that sort of works out of the box. I was trying to make a backup of /var/spool/caldavd, preserving the extended attributes, when discovering that Ubuntu's tar does not have a --xattr switch. The same version of tar on my Fedora boxes do support that. Is that a Fedora extension, or an Ubuntu omission? What do Ubuntu people use to backup files with extended attributes? Thanks, Pim