Since I have been using rdiff-backup to backup my Xen domU machines, I get a daily message from cron which informs me that some sockets couldn’t be backed-up because the path is too long: SpecialFileError var/spool/postfix/public/flush Socket error: AF_UNIX path too long After some digging I have found that this is related to the length limitation of the AF_UNIX constant in one of the kernel header files, and which only allows 107 characters. Depending on where you want to backup to the length can exceed. The solution is simple. WhyContinue readingSuppress socket warnings when using rdiff-backup