I am building an OpenSolaris box to attempt to use ZFS and RAIDZ. I am starting simple with the OS on one drive and wanting to store all my data on the RAIDZ volume. I am a bit confused on RAIDZ is handling parrity. I created a pool using the command "zpool create pool_1 raidz drive1 drive2 drive3" and when i did a zpool list it shows the available size of the three drives together. I figure if the parity was automatically calculated it should be short the size of 1 drive. So I deleted that pool and created one using "zpool create pool_1 raidz drive1 drive2 spare drive3" and the available size was what I expeceted to see. To me a hotspare isn't parity though it is a disk that is ready to fill in for parity in the event that your raid loses a drive. I don't want to get down the road and have one of those two drives fail and find out no parity.
Any explanation on this would be much appreciated.