This is my personal expirience from a heavy NFS Site. Which lead to replacing 2x7000/600 Auspex Netservers with a F740.

To get realy good write performace lets say that you have to use atleast 7 drives/raidgroup.The performance raises up to lets say ~14. 7 drives without parity ( raid 4 or 5 ) is not verry funny considering the risk of a failing drive , restore times etc.

So, in the Auspex case i had to go for mirrored stripes. ( Very bad price/performance and i finaly grew out of my cabinets )

On a filer i spend money on one "extra" drive instead of seven.

The 740 is just cruising with the load which lead to the fall of the Netservers.

Not to even mention the decreased need of administration.

Anders Ljungberg

As Jeff said, Netapp's RAID-4 implementation is not performance limiting in most cases. Most of the time a filer with RAID-4 will provide better performance than an equivalent product without RAID or with RAID-0. So I'm sure you will be quite pleased in your tests, particularly against a (*snicker*) Auspex. (Be sure to compare the price and number of filesystems in each system configuration as well.)

I seem to recall some public talk waay back when about Netapp possibly offering RAID-0 since basically all you have to do is remove the parity drive. You could simulate this yourself by manually failing the parity drive and letting the filer operate in degraded mode with just the data disks. However, I'm not sure that the code is actually optimized for this case, so there might be some other normal RAID-4 checks that get in the way of realizing any performance gains.

Bruce