RAID: use raid controller, card, MB, or software?

elliot100

elliot100

elliot100

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Hi, I wanted to build a server for home use, primarily for backup, but maybe also for media and web dev server in the future. So I decided I needed Raid 1 (mirroring) over 2 drives to start with.

Bought a cheap and cheerful barebones machine, added a couple of big, quietish, drives, all from OCUK - no problem there. I assumed I wanted 'proper' hardware RAID so added bought a quite expensive Adaptec RAID controller card. System runs Win XP and boots off the RAID.

But I think I've made a couple of mistakes. Guess I should have researched more...

1. Booting: Seems that it's not common practice to have the OS as well as data on the RAID volume, and therefore boot directly from the RAID, at least not when you use a RAID controller card.

And it doesn't work 100%: It boots fine from a power off/on at the PSU, but when restarting from Windows, or using front panel power/reset buttons, the RAID card never sees the drives. Which is annoying when I plan to run the machine headless under the stairs.

So looks like I should really have a 3rd drive for the OS, and boot to that?

2. RAID hardware: If I understand correctly, RAID systems are proprietary so I am tied to the RAID card's manufacturer. I guess I assumed that if the system melted down, the drives could be plugged into another RAID card or motherboard with RAID support. If not, this seems a bit worrying. If you're using RAID on the motherboard, how are you supposed to move to a new motherboard, for example?

Any suggestions? Do I just use software RAID instead (which I think I'd need XP or Vista Pro for?). Or FreeNAS (but I think this would rule out running Apache?) Or do I start messing around with virtual machines?

Getting a bit out of my depth here so any suggestions welcome.

Cheers,
 
1) There's nothing wrong with booting from a RAID volume, there are plenty of folk on here who do. Generally in a server environment the OS and data are separated but still on RAID arrays (our standard is RAID1 for the OS and apps then a larger RAID5 array for data but that varies depending on the machine role).

If the card can't see the drives from a soft boot then there's something very wrong somewhere. What model of card is it?

2) RAID1 is far less pernickity about controller compatability than the likes of RAID5 but it can still be fussy. Generally an array can be moved to a controller from the same manufacturer but that's not a hard and fast rule. If you want to move an array to a new board then you need to be using either a controller card which can be moved or you're restoring from backups.
 
As above.

On a server having the OS on a RAID volume is normal. I prefer to have separate RAID volumes (on different drive sets) for the OS and Data but it's not necessary.

In my mind a dedicated hardware RAID card is always preferable and you shouldn't have any problems booting/rebooting from it. As you are having problems I’d suggest that you contact Adaptec and see if they can help.

For a simple RAID1 volume a hardware RAID card is probably overkill as there’s virtually no processing overhead that the card can help with. If you’re planning on RAID5 (or RAID6) in the future then it’s worth having the card.

You are correct is saying that RAID systems are proprietary. If the card dies you’ll need to get hold of a matching card to transfer the drives onto. Luckily RAID cards are pretty reliable and will normally far outlive the attached drives.

You should remember that RAID is not a replacement for a proper backup solution. All RAID does (ignoring RAID0) is add some extra redundancy that should hopefully allow you to survive the occasional drive failure. At some point you can more-or-less guarantee that you’ll lose the array for some reason or other and you’ll need to be ready to restore from your backups.
 
Cheers. Not sure why I typed Adaptec, it's actually a Highpoint Rocketraid 2310. Obviously have already searched for boot problems related to that device, checked for updates, etc without any pointers.

Have now checked Highpoint's website and found there are only 20 supported motherboards across all Highpoint cards (http://www.highpoint-tech.com/PDF/Compatibility_List.pdf), and of course mine isn't one. Looks like I have bought quite a specialist device...

I'm going to have to rethink this from scratch, but if controller cards are that fussy I guess I'm better off with a mainstream RAID-supporting motherboard, or maybe software RAID, and flogging the Highpoint.

Re backup - should have said that everything on it now is a backup of what's already stored on other machines, and if I do host media or dev websites, will work out another backup scheme.
 
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The 2310 should be OK. I use a 2320 here (which is essentially just an 8 port version of the 2310) and neither board that I've used it in is on the compatability list.

I'd also recommend doing a firmware flash, it's an easy process in Windows.

When you say it's losing the drives on a soft boot is that the drives not being detected by the controller BIOS or the array not showing in Windows. Reason for asking is I had to disable the (I think) INT13 feature in the RR BIOS to get Windows to detect the array correctly. I'll have a dig and see if I can find anything more on that.
 
Id have thought that for the purposes of home server, either the Intel onboard raid or os-level software raid would be more than adequate. I have one 30gb drive for the os, and a raid 5 organised in software for data. This machine is acting as a home server, streams media quite happily.

I always avoided hardware raid for fear of being unable to migrate hard drives from one machine to another. I've moved my drives from a p35 board to a p45 and the array didn't even flinch, just picked itself up and worked.

If the hardware card is faulty, then perhaps software is the better option?
 
Hi - sorry have been a bit busy... Thanks for suggestions.

The issue is the drives not being detected by the controller BIOS, not the array not being seen by Windows.

I guess I will check the BIOS is up to date and if still issues will probably go to a software system.
 
I've got a similar setup to you. I'm just using a cheap SATA/RAID card off egay (Silicon Image SI3112) and to be honest it's perfect for my needs.

When I first set it up with 2 1TB WD Greens in Raid 1, the card couldnt detect the drives properly, it would start detecting one, would show its model number and then couldnt get any further. I flashed the bios of the card to the latest one and it now see's both drives fine (I guess it had some trouble seeing 1TB drives?)

I've got my OS and data all installed on the array and boot from it regularly. Everything was fine up until the weekend whent he array decided to drop one of my drives, and then from my tinkering and testing I pretty much destroyed the array. It wouldnt boot from any drives and kept moaning it couldnt see an OS (but would detect the drives fine).

In the end I just formatted and restored my data from some backup's I'd made. Everything is running fine again now (As has been said, always keep backups of your data just incase. Raid 1 can protect you better agains drive failure but if the whole array goes down, bye bye data). At the end of the day it's a learning experience lol
 
surly as raid1 is just mirroring (am i right there?) then it shouldnt matter if the raid card fails?

couldnt you take one drive out and plug it in as a standalone and it would still boot? the raid card isnt doing anything special just mirroring everything. its not like raid0 where its scattering stuff acrross both drives... im a bit confused lol
 
Unfortunately life isn't that simple. In my experience if you take a drive that's part of a RAID array of any sort and try and connect it directly there won't be any recognisable partitions available.

The one exception I know of is software RAID1 via Windows (and probably Linux but I've never tried) where the drives can be read individually. If you couldn't then the system wouldn't work in the first place.

All my dealings with RAID arrays have been with real hardware RAID adapters, mainly using SCSI and SAS drives. Things may be different when you're using the RAID capabilities provided by the motherboard chipsets, but I doubt it.
 
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