I am just curious WHY you want to use optical drives. You can get 4T drives for $4.50 a Terabyte, one 4TB drive is about more compact than a stack of 100 50G blue ray. Why would you choose to make optical disks.
my pricing information comes from:
If you did the above things with the cheapest 4TB drives on amazon…
$268 16 external SAS channels
2 at $70 each
48 at $18 each, initially $429 each, 48 for $968
Storage review did a review of one of the 10TB drives in this line.
ie 8ms, 450MB/sec
4 external cables at $20 each
12 at $20 each SFF-8643 to SFF-8482 Cable
make a pair of raidz3 arrays, 2 hot spares per chassis, add both to a pool, so 19 drives of effective speed.
219TB = 152TB in the pool at 17GB/sec read, as slow as 4.25GB/sec write with large files since writes have to go to at least 4 drives,
268+968+140+80+240 = $1696 for 152TB
plus a box and power supply and fan, and somewhere to put it out of earshot. Hard drives consume about 7W while they are on so these hard drives will use 336 watts plus the controller cards.