I have an amd64 server running 7 Beta 2. It is exporting a ZFS-based filesystem with NFS. My Mac OS X (Tiger) client is having problems with the NFS filesystem. Things work fine from the shell, but the Finder is unable to create files on the ZFS-based filesystem. I made a trace with ethereal of a successful file write to a UFS partition and an un-successful write to a ZFS partition. In frame 15 (17 in nfs.bad) a CREATE call is issued, with the filename and a mode of EXCLUSIVE (2) Frame 16 (18 in nfs.bad) is a response, showing the MODE as 0000 Frame 17 (19 in nfs.bad) is a SETATTR call with a new mode of 0644 Frame 18 in nfs.good is a SETATTR reply which shows the new mode as 0644 on the UFS disk ... Frame 20 in nfs.bad is a SETATTR reply which shows the new mode as 0000 on the ZFS disk Frame 22 in nfs.good is an ACCESS reply which shows the mode as 0644 on the UFS disk ... Frame 24 in nfs.bad is an ACCESS reply which shows the mode as 0000 on the ZFS disk it also shows that MODIFY and EXTEND are disabled. The Mac then creates a file for the mac-metadata in mode UNCHECKED (0) and mode 0644, and that goes ok in both traces. In summary, it appears that ZFS does not allow SETATTR to change the file mode, at least in the case where it is zero, and UFS does. The mac is apparently using NFS version 3, if that matters. The traces are too large to quote here, if they are needed to track this down further they are: http://www.tgsoft.com/nfs.bad http://www.tgsoft.com/nfs.good -mark