zfs discuss - Aug 2008 - What''s the best way to get pool vdev structure information?

For various sorts of manageability reasons[*], I need to be able to
extract information about the vdev and device structure of our ZFS pools
(partly because we''re using iSCSI and MPXIO, which create basically
opaque device names). Unfortunately Solaris 10 U5 doesn''t seem to
currently provide any script/machine readable output form for this
information, so I need to build something to do it myself.

 I can think of three different ways to do this:
* parse the output of ''zpool status''
* write a C program that directly uses libzfs to dump the information
  in a more script-readable format
* use Will Murnane''s recently announced ''pyzfs''
module to dump the
  information (conveniently I am already writing some of the management
  programs in Python)

 Each approach has its own set of drawbacks, so I''m curious if people
have opinions on which one will probably be the best/most stable over
time/etc. And if anyone already has code (or experience of subtle things
to watch out for), I would love to hear from you.

 Thanks in advance.

	- cks
[*: for example, we need to be able to generate a single list of all of
    the iSCSI target+LUNs that are in use on all of the fileservers, and
    how the usage is distributed among fileservers and ZFS pools.
]