ZFS question

How does ZFS keep track of drives in a dataset or VDEV? If I rearrrange the drives in a chassis, somehow ZFS is able to make sense of the scrambled drives and 
mount the dataset.

Clearly ZFS is tracking the drives. How does it refer to the drives internally? By UUID, Drive Label?  On some  OS’s (Linux) there are many options for specifying which drives make up a VDEV: UUID, Partition Label, etc. On other OS’s, these schemes might not exist
(think moving drives from Linux to FreeBSD, for example).

I’ve noticed that on Linux, drive identifiers (sda, sdb, etc) move around after reboots. How does ZFS cope with this?

Does each drive (or partition) have a header that tells ZFS that this entity is ‘drive 2 of VDEV foo’?

Thanks,

Joe

Joe McGuckin
ViaNet Communications

joe@via.net
650-207-0372 cell
650-213-1302 office
650-969-2124 fax