Question on ZFS and redundancy

[Andy Young]

In the past I've used multiple RAID6 volumes under Linux. The thing I
disliked about this was that my code had to worry about splitting my data
across the volumes. I had to worry about which ones were full and manage
all of that complexity myself. However, the volumes were independent. If I
lost three drives in a volume then yes I would lose the volume but it
wouldn't affect any other volumes.

Now with ZFS and raidz2 I love the fact that I can use a single pool to
spread data across multiple vdevs. However, the vdevs aren't independent
anymore right? Because ZFS stripes data across the vdevs, if I lose three
drives in a single vdev, doesn't this put the entire pool at risk?

Andy