Decided on the Dark Side and I want to build a 120TB Monster and WOW, do I have questions.

[Bhoot]

Another comment would be on the number of parity drives. The op is kinda sorta walking on very thin ice. If it were upto me, the minimum I would go would be 2 Vdev 8disk each on Raidz2.

 

[Constantin]

2x Raid z3 with eleven drives per VDev would fill 22 slots in a 24-drive enclosure and leave 2 open for L2ARc, boot. You’d get the desired data capacity. SLOG, if necessary, should be via faster busses.