How many drives & RAID controllers would I need?

[zalant]

The server I'm being asked to spec out requires both a RAID 1 and a RAID 10 configuration. It's my understanding that RAID 1 requires at least two drives and RAID 10 requires at least four, so that's at least six drives right there. Further, I've seen recommendations that state to avoid installing the OS on any of the drive in the RAID volumes, and just to install it to the motherboard's regular hard drive controller. That would put me at seven drives, total. My biggest question is, can one single RAID controller handle both the RAID 1 and the RAID 10 setups? And the more stupid/newbie type question I have is, do hard drives plug directly into a RAID controller, and if so, can you plug in up to six in one controller? Do the hard drives plug into a drive cage and then the cage plugs into the controller?

Any advice on setting this all up would be hugely appreciated.

 

[adampower]

Sure you can do this with a single RAID drive controller. Most modern mobos will let you do this onboard.

Use FreeNAS and put the OS on a usb stick or an ide to cf device.

Yes the drives plug into the card. Use PCIe and not PCI if you must have a RAID controller. Yes, you can plug the drives into a drive cage and then the controller if this is your wish. You can buy a hot swap bay and do that. I'm not sure which way you're prepared to go and how deep into FreeBSD, Linux, Windows Server, etc. you want to go.

Check my thread if you are interested in my dream NAS box. Configure it any way you wish.

http://www.tomshardware.co.uk/forum/257857-14-freenas-system-gigabit

 

[zalant]

This is for a medical clinic running a 3rd-party database application. (The specifications actually came from the manufacturer of the DB app.) The server that Dell is quoting us has a PERC 6/i RAID controller and the chassis has room for up to six drives, which is why I'm concerned about needing seven. As this is for a medical business, it has to remain very Windows (required), very by-the-book. I'm pretty sure that loading the OS on a flash drive might be a bit "out there" for this scenario.

With respect to the physical drive connections, we're considering SATA II hard drives. Will a RAID controller have 6 SATA ports on it? Is that why drive cages are used? Sorry to ask the simplistic questions, but I need to have an iron-tight grasp no this before the purchase of a server. The OEM's I've contacted won't configure both a RAID 1 and and RAID 10 setup prior to shipping the machine.

Thanks for your previous reply, BTW!

 

[rofl_my_waffle]

Why do you need RAID 1 and RAID 10?

Just to clarify, RAID 10 is known as RAID 1+0. Basically two RAID 0 configurations in parity. Hence the 0 and 1.

I don't see why you need to run RAID 1 as well as RAID 10. Why not just a bigger RAID 10 which is more efficient. The chances of simutaneous drive failure of the same mirror is practically impossible.

I highly recommend an SSD for windows since RAID doesn't improve seek time which is important for random read in windows.

 

[adampower]

If you will must use windows server you could choose which partition to place it on and carry on. Or, you may have a PATA connection and use an ide drive for the OS.

It is interesting that the OEM's won't configure both arrays. Perhaps the PERC 6/i will not allow both a RAID 10 and RAID 1 simultaneously? Or is it just too much work for them?

 

[zalant]

The database software provider requires a RAID 10 (1+0) configuration for the actual database, and the RAID 1 volume to handle log files. I realize that it may not make sense to everyone, or perhaps may be a bit of overkill, but those are their specs, and if we want them to provide support for our installation of their software, we kind of have to play by their rules.

As for the included hardware RAID controller handling both RAID configs simultaneously, that I really need to look into, but should all else fail, it's possible that the motherboard may have RAID 0 and 1 ability built in, so I could configure a RAID 1 setup via that for the log files.

 

[nocheese]

A) What "Rofl_My_Waffle" said. Although there are certain benefits to having a separate RAID volume just for the DB. The boot and installed applications themselves (like SQL minus the actual DB if it's on another volume) are often on the same RAID volume.

B) Who says not to boot from a RAID volume? That's crazy. For maximum up-time you most certainly want the boot system to be on a redundant volume.

C) I hope this exercise is for information only and not because you want to "home build" a server for use at a medical clinic.

 

[zalant]

Thanks to all!! I think I have the info I need. Don't worry, nocheese, Dell is putting this unit together and will be supporting it for at least a few years. We just have to tell them exactly all that we need to support the DB app. We need Windows Server 2003, though, so they won't be putting that on it, nor will they setup both RAID configs. We'll have to do those things once we get a hold of the machine.