If you the choice to make again, would you buy another Network Appliance, or would you get the biggest disk array you could find for the same money? Why?
*provided i needed RAID5*, that's a no-brainer. it's noticeably better than any of the other RAID5 offerings i've tried, and likely cheaper than RAID0+1 with anyone's discs and arrays.
Thanks for the kind words! However, lest anyone get too confused, our filers use RAID-4, not RAID-5. Still parity and the same degree of data protection, just on one disk instead of being interleaved amongst all disks as RAID-5 does. The advantage of RAID-5 is that you can use a traditional file system, designed for a single disk and not for RAID, and distribute the parity workload amongst the disks instead of it being focused on one disk. NetApp uses a file system designed for RAID to avoid the parity disk bottleneck.
RAID-4 has the advantage of allowing you to expand the RAID group (even by just one disk), and of using disks of varying geometry in the same RAID group. RAID-5 requires all disks to have the same geometry and cannot itself be expanded, though you can expand the filesystem by concatenating an additional RAID group (not just one disk, and more space is lost to parity).
-- Karl