nickstilianos

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Dec 19, 2006
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I had a Intel 955BX board with two 74G raptors in a RAID 0, and three 250G drives in a RAID 5. With this new board I loaded my Raptors on the intel SATA connectors with a raid 0. But I want to use the 3 250G'ers on the Marvell controller in the same RAID5. It wont let me do it. I only get the choice of 0 when loading drivers from floppy. How would you guys suggest I set this up. Would it be better to use the Marvell for the system RAID and intel for the RAID 5.

Intel D975XBX2
1G. Crucial Ballistix Tracer (512 X 2)
EVGA 7800GT
WD Raptor 74G X 2
WD Cavier 250G X 3
Lian Li Case
Dell UltraSharp 2407WFP
 
I don't think that very many OSes can install onto a purely software RAID setup (except for RAID 1) so my suggestion is to use the Raptors on one controller and the 250GBs on the other. You only need to ensure that the Raptors are on the same controller and that you can boot Windows off of that RAID array using it. You could stick the 250GB drives' cables off of any SATA port you want if you are willing to set up RAID in Windows rather than in BIOS. There's no real difference in performance as it's all software RAID anyway and you don't need the 250GB drives to be seen as one disk at boot time.

However I would warn you that putting your OS on a RAID 0, while it *is* fast, is asking for trouble. I've seen too many HDDs die to want to do that. And unless you have an image of Windows with all drivers, registration codes, applications, and whatnot already in it, installing Windows is a real PITA.
 
Yes, Intel's RAID setup has BIOS hooks so it can be booted from. I think that I at least alluded to that; if not, I didn't mean to mislead anybody. Intel's ICH array is a classic fakeraid- not a fully hardware RAID setup (such as a 3Ware Escalade RAID card) because the host CPU does some of the work, but it's not a full-on OS-driven software RAID like Linux md or Windows Dynamic Disks either. The latter requires the OS to start up so that the RAID modules can be loaded and the array initialized and mounted. Real hardware RAID and fakeraids appear to the OS as a single disk at bootup and can be booted from, true software RAID appears as a group of disks at boot and generally cannot be booted from (with the only exception that I know of is that Linux can be booted from a software md RAID 1 disk.)

That's why I suggested that he connect the Raptors to one controller- one set up in fakeraid mode- so that the OS can see it as a single disk and install to/boot from it. The 3 250 GB disks can be set up either as a fakeraid too or handled entirely in software. It does not matter as the OS is able to load the RAID modules and start the RAID since it's not using those disks to boot from. It would be a matter of personal preference at that point.
 

nickstilianos

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Dec 19, 2006
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Thanks for the help. So I need some advice. I already have my system raid @ RAID 0 with the 2 Raptors. It works fine. Someone comented that its not safe with the RAID 0 because of drive failure and losing windows. I don't really care about having to reformat, I do it every 6-8 monthes any way. I want a method of keeping my critical data safe, pictures, programs, XXX video etc... Now I have these 3 250G drives that I want to use in a RAID, but just like when I upgraded my MOBO I had to back up my RAID 5 on an exertnal and now rebuild the RAID on the new hardware. Now the problem is I don't want to have to back up, I want the RAID to carry over. From what I heard from other is I shoule get a seperate RAID controller card. I've looked on line and they are upwards around $300+. Can someone recomend a cheaper card, or better advice. I was also considerind a external Netword raid device , which seen to be popular now. Any advice will be greatly appreciated...
 
Since you reinstall Windows every 6-8 months anyway and are also doing RAID 0 on two excellent, enterprise-grade drives you should not have any problems with RAID 0. RAID 0 isn't *that* unreliable with the kinds of hardware you're using- my guess is it's many years before one of the drives gives up the ghost. The problems with RAID 0 is when people did it with cheap 1-year warranty IDE drives in the 1990s and put critical data on the array. Today's drives are much better as even the cheapest ones carry 3-year warranties and the better ones like the Raptors and Caviar REs carry 5-year warranties. The warning about RAID 0 is not that something bad will happen, only that it can and to make good backups, otherwise "we told you so." But that applies equally to a single drive as well as there's no parity information to recover it either.

RAID 5 is a relatively efficient and safe way to store a bunch of data. Like any other RAID array, you will have to rebuild it when you change controllers. So if you use the controller on the motherboard through the BIOS, you have to rebuild your RAID setup if you get a different kind of motherboard. (A replacement mobo of the same kind should not require a rebuild and one with a similar chipset should also work in theory.) The same holds true for external RAID controller cards too. You get a different card, you need to rebuild your RAID. But a RAID controller card + the drives can be moved from one box to another and not require a rebuild.

The option that requires a rebuild the least would be software RAID mediated by the OS. You could in that case plug your disks into any computer running a similar OS and having enough disk connectors and your RAID would carry over. You would not have to ensure that you only use the Intel ICH SATA ports or just the Marvell SATA ports in a single array if you did software RAID as the OS only cares that it can see the drives. You can also mix and match IDE and SATA as well for the same reason. Software RAID is extremely flexible and much cheaper than any hardware RAID of BIOS fakeraid setup. It's also as fast or faster than about any sub-$1000 hardware RAID card too. You also do not have to use an entire drive for an array too- you can RAID together partitions if you like. You could partition the drives into two equal parts and make one 250GB RAID 5 array out of the first partition on each drive and one 375GB RAID 0 array out of the second partition on each drive if you wished to. About software RAID's only drawback is that you can't boot straight from a non-RAID 1 software RAID setup, but your Intel ICH fakeraid on the Raptors makes that a non-issue for the 3 250GB drives. So if I were you, I'd go with pure software RAID either through Windows Dynamic Disks if you run Windows or md RAID/dmraid if you run a UNIXy OS. I personally run a pure software RAID 5 on 3 250GB drives set up in Linux using md. I've been extremely pleased with the performance and flexibility of it over other RAID methods.