Hello all, seems that I was able to resolve issue with No space left on device. Seems that there is some kind of bug inside calendarserver. When using separate filesystem for Document root, document root cannot be in the root directory of attached filesystem. For example, if in caldavd.plist is Document Root at /var/spool/caldavd, you cannot attach filesystem to /var/spool/caldavd. Only way to resolve it is either make new filesystem at /var/spool or move documentroot to somewhere like /var/spool/caldavd/documentroot/ After that I received no more error messages. (However I didn't receive any email notification, but I think that's an other story...) Best regards, Ladislav