Bigass ZFS raidz3 array

[Relativistic]

I'm thinking of doing the following for my new home media server.

12 x 1.5 TB drives in raidz3 (either WD GP or Samsung EcoGreen, can get them for ~€70 each)
This will yield a total of ~12 TB of usable space.

Does anyone have experience with big ZFS vdevs like that? Cheapo drives like the ones mentioned should fail pretty regularly, and the triple redundancy will come in handy in these situations. Is TLER or Samsung's equivalent really a concern, or am I being paranoid here?

The CPU I'll be using is a 3ghz C2D. I don't care if it's going to be slow... anything over 30 MB/s is fine in my book.

 

[unhappy_mage]

Wide stripes like that will give you very slow random reads: at least 9 of the 12 disks need to read their part of the stripe before it's even possible to start giving you data, and in practice all 12 are read.

I'm using a controller which apparently has known problems with SAS expanders, which causes timeouts to happen. This is apparently not related to TLER-like features but a bug in the driver. So you may or may not get timeouts.

I get much faster read speeds from my 6-disk raidz2 than 30 MB/s: up to 200 MB/s when it's not stalled from the SAS expander problem. The stalls last maybe ten seconds.