Here is an unpleasant discovery that we just finished making: in atleast Solaris 10 U6, ZFS changes the device numbers of all of yourfilesystems when your system reboots . More specifically (and evenworse), the device numbers of a pool's filesystems change wheneverthe pool is imported, including the implicit import that happenswhen a system boots up.

(This raises interesting questions of how NFS filehandles keepworking across system reboots, which they do. Presumably theyhave some other stable identifier for a given

For my own future reference and because the SystemTap wiki is not the clearest thing onthis, here's what packages are required to be able to use SystemTap onvarious distributions.

We use the -server kernels on our Ubuntu 8.04 machines, so I neededto do:

apt-get install systemtap linux-image-debug-server linux-headers-server
ln -s /boot/vmlinux-debug-$(uname -r) /lib/modules/$(uname -r)

Python frame objects have a tempting member called f_locals , whichis described as the 'local namespace seen by this frame' (to quote the inspect module ). This isslightly misleading, because it is not always what Python programmersnormally think of as 'locals'.

Specifically, if the frame comes from code that is running at themodule level, f_locals is the 'local namespace' of that code,that is, it is the module's namespace. In other words, it'