71 TiB DIY NAS Based on ZFS on Linux
I have a similar capacity solution running at home, though I have far more (fewer disks per) vdevs. I've been running it for a few years now, so some things aren't as optimized as they could be, but it still works well for my uses...  # zpool list
  NAME      SIZE  ALLOC   FREE    CAP  DEDUP  HEALTH  ALTROOT
  lanayru  73.3T  53.7T  19.6T    73%  1.00x  ONLINE  -

  # zpool status
    pool: lanayru
   state: ONLINE
  status: The pool is formatted using a legacy on-disk format.  The pool can
          still be used, but some features are unavailable.
  action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
          pool will no longer be accessible on software that does not support
          feature flags.
    scan: scrub repaired 1.58M in 201h47m with 0 errors on Fri Feb 21 13:37:24 2014
  config:
  
          NAME                                                  STATE     READ WRITE CKSUM
          lanayru                                               ONLINE       0     0     0
            raidz2-0                                            ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
            raidz2-1                                            ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
              ata-SAMSUNG_HD204UI_______________-part1          ONLINE       0     0     0
            raidz2-2                                            ONLINE       0     0     0
              ata-ST2000DL004_HD204UI_______________-part1      ONLINE       0     0     0
              ata-ST2000DL004_HD204UI_______________-part1      ONLINE       0     0     0
              ata-ST2000DL004_HD204UI_______________-part1      ONLINE       0     0     0
              ata-ST2000DL004_HD204UI_______________-part1      ONLINE       0     0     0
              ata-ST2000DL004_HD204UI_______________-part1      ONLINE       0     0     0
            raidz2-3                                            ONLINE       0     0     0
              ata-WDC_WD30EFRX-68AX9N0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68AX9N0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68AX9N0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68AX9N0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68AX9N0_WD-____________-part1    ONLINE       0     0     0
            raidz2-5                                            ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
            raidz2-6                                            ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
              ata-WDC_WD30EFRX-68EUZN0_WD-____________-part1    ONLINE       0     0     0
          logs
            mirror-4                                            ONLINE       0     0     0
              ata-KINGSTON_SV300S37A60G_________________-part1  ONLINE       0     0     0
              ata-KINGSTON_SV300S37A60G_________________-part1  ONLINE       0     0     0
          cache
            ata-KINGSTON_SV300S37A60G_________________-part2    ONLINE       0     0     0
            ata-KINGSTON_SV300S37A60G_________________-part2    ONLINE       0     0     0
  
  errors: No known data errors

If anyone has any questions, I'd be happy to try to answer.