Post your performance results

jching wrote:

Helevitia wrote: The NV is definitely the bottleneck here. But if you compare the NV to the competition, you will see that not many are faster(plus these support forums are worlds better than the competition which is why I bought an NV). In time, as NAS devices become more popular, speed will become a bigger factor, but for now it's not to most people. If you're refering to Buffalo or similar, than yes. I agree. But how about FC RAIDs, like Medea, Infortrend, Xyratec. Granted, these are fiber channel, so they get 280+MB/s with 6 disks. This is about 50MB/s per SATA drive. Which is what I would expect from a SATA RAID system. But even if we're limited to gigabit Ethernet, I'd expect greater than 30MB/s. So why is the Buffalo/NV/Thecus/etc so slow in comparison? Why aren't they getting similar performance from the SATA drives? Exactly what in the NV is the bottle neck? Is the RAID operations done in software? Is the parity done by the CPU? Aside from the fiber channel vs. gigabit ethernet, what is different between the Medea/Infortrend vs. Infrant/Buffalo? --jc

Fibre Channel RAID is controlled by the host bus adapter of the machine to which it is attached. This is a SAN (storage area network) which is completely different to a NAS (network attached storage). Because the disks in the NAS are controlled by the NAS (a computer itself), there is an extra overhead in communicating with this separate computer, caused by a) ethernet latency; b) cross server latency; c) inter-process latency, all of which delay the NAS from responding that it has written each packet of data.

If you really want performance, even SANs don't hack it -- the maximum throughput for a single HP fibre channel host bus adapter is currently 4Gbps (that's gigaBITS with a small 'b', i.e. 512MBs). However most of the SANs out there only support 2Gbps. Compare that with a four channel HP 6404 raid controller which has 4 x 320MBs (that's megaBYTES with a large 'B') = 1280MB = 10240Gbps. Quite a difference. Of course you'd need a server with PCI-X slots or the like and enough disks to soak up that much IO, but that's what's possible