PORTABILITY

Here are notes on cross-platform issues. Notes to myself on what features
may or may not be available, and tradeoffs for each.

zfs list -d X
	Present in Solaris 11, 10MU10, nexenta 3.1.3
	Gives ability to "nest" zrep managed filesystems

zfs send -p
	Present pretty much everywhere.
	Allows auto-copy of properties on src filesystem.
	HOWEVER: may cause problems if -x is not functional for recv
	See -x lower down

zfs receive -x
	Present In MU10, but not MU6.
	Not present in nexenta.
	Allows filtering of "mountpoint" property
	WARNING:  would be nice to use it morethan I do, and
	use -p all the time... but it is buggy :( does not
	always exclude the property I want it to.

Setting properties on SNAPSHOT, not just filesystem
	Present in MU10, and nexenta. Not present on MU6
	Currently used to set a per-snapshot timestamp of
	when it was successfully sent.
	There is some reason why I prefer NOT to just do
	the fallback, of setting that information in the
	parent fs, but I'm not remembering it clearly. It was
	after a long debug session sometime.
	:-(

	May have been when I was using send -p, so didnt want
	older value synced.
	And/or, may be to allow sometime in future, multiple snap
	trees, for multi-machine syncs
	(but that would require significant rewrite, of our zrep:xx props)

	Still seems kind of conceptually nice,when you have multiple
	snapshots,to have a record of when each was sent.
	Perhaps it is for purposes of ROLLBACK.
	If you ever roll back on the master, a "last synced" value set
	on the parent filesystem is then misleading/inaccurate, until next
	sync

	
zfs get -s (local,)received
	Present in MU10, and nexenta. NOT in MU6!!
	Allows us to filter for properties that got transfered
	via just "send -p", rather thanhaving to manually
	   "ssh $desthost zfs set xxx"
	to make it local

	Used to us this more, but I think transitioned to
	using direct set for everything,to make compat easier.
	But this adds much latency for short stuff :(