Quote:
|
Originally Posted by blue68f100
Has any one confirmed that the 4100 is using a hardware raid controller or using a deciated controllers with software raid??????
|
Ya know, funny you should ask. I have seen you (and others) say this on a number of occasions (about the 4100 using hardware RAID). I always wondered where you got that idea from, but just "assumed" you were correct and moved on with no reason to doubt you. From pictures I have seen of the 4100 circuit board, and I admit it is hard to tell that way, it did not look like a hardware RAID based controller to me. The "hardware RAID" comment always struck me as a bit funny, but as I said, I just assumed you were right and had no reason to question it. Now that you mention it, it looks like a software RAID setup to me, but I do not have a 4100 and thus cannot confirm one way or the other. Anyone else?
For someone that has a 4100, look at the main chips on the circuit board, get the numbers, and then look them up with some internet searches. This will tell you for sure... In most (not all) cases, the chip doing the XOR operations for RAID 5 is a larger, cpu type, chip. It is usualy just that, a genera cpu or a dedicated XOR cpu chip. Thus, not hard to find or look up... Without this dedicated XOR chip, it cannot be doing Hardware RAID 3, 5, 6, or any RAID using parity with XOR calculations.
Now for the catch 22... All of this is a matter of perception. In a workstation or server or whatever type PC where we refer to hardware and software RAID, what is being talked about is if the controller does the calculations and work for the RAID or if the calculations and work for the RAID are being offloaded (at least in part) to the PC memory and processor through software (the driver). There is some stuff in here for the other RAID modes, but where it becomes serious is with RAID modes that use parity XOR calculations (RAID 3, 5, 6, etc). Depending on the number, speed, and size of the drives being used, this can be a lot of cpu load.
So, in a PC, a "hardware" RAID is prefered so as not to drag down the PC, plus the "hardware" RAID is usually faster as well (and more reliable). Fact is tho, this "hardware" RAID is still doing it in software to a minor extent, just not in a driver, but rather in firmware on the controller board, sort of. This is not exact, but this description keeps it simple.
Now in the case of a SNAP (or some other type NAS units), the unit is not doing anything else much other than maybe some web interface stuffs and the like. The cpu on the SNAP/NAS motherboard is not really being used for anything other than this minor web interface stuff and the RAID work. The software RAID driver is built into the OS, and so, in a way, the SNAP motherboard is in a way, like a hardware RAID controller board. Maybe not quite as efficient, but very similar. I guess a way to look at it is that the SNAP controller boards are a hybrid hardware RAID sort of.
In other words, it may all be a moot point, so long as the software (OS) is effective, efficient, and reliable. The only real concern is the cpu and memory on board. Some of these units are getting along in years, made back when the largest hard drives around were like 30 GB and less. The cpu and memory expansion abilities may not be enough to do the heavy lifting for some of the much larger arrays we can create now days with much larger and faster drives. But then, with the limitations we are finding in the OS, well....