> > if a coraid appliance were pcie-attached rather than ethernet attached, > > would you still ask this question? do you think the block diagram of coraid > > hardware looks fundamentally different than the block diagram of a raid > > card? > > It's just curiosity. I know the appliance is Plan 9 based. If it > uses an off-the-shelf RAID chip I might buy a card with that chip > since it works in Plan 9. If it's fs(3) I know fs(3) is good enough > for my needs. If it's something else at least I know fs(3) is not > good enough and I might be tempted to write something myself. So yes, > I'd ask even if it was a PCIe card instead of network appliance.
the motivation behind my question is that it's not clear to me that there is such a thing as pure hardware raid. if someone knows of something that implements the entire read/write path without a cpu, even with a degraded or rebuilding raid, i'd be very interested in that. but as far as i know, there's always a processor in there on the other side of the bus. in case of aoe, the bus is ethernet and for a "hardware raid" card, it's usually some form of pci. (see wiki's raid article.) - erik
