November 11th, 2008, 03:28 PM
[RESOLVED] RAID 1 to RAID 0 ?
I purchased a Dell T7400 quad about 10 months ago and soon I realized that I made a mistake in specification. I have two HDDs 300GB each and I asked for RAID 1. The nature of my work requres speed not data safety. I regret it very much although the machine is very fast. Perhaps I could have increased the speed by a factor of two or more had I had RAID 0?
Is it possible to change it now?
I do have a warranty. Do you think it is a good idea to contact Dell and ask them for assistance or I can do it myself if it is possible?
November 11th, 2008, 03:33 PM
It would be faster, but the performance would not DOUBLE by switching to RAID0.
I'm guessing you have a method of backing up the system if you plan to use RAID0, so I won't go into that.
The nature of my work requres speed not data safety.
You can't simply change from RAID1 to 0, or vice versa. You would have to create a new array, which would wipe out all data on the drives. You could make a backup, create a RAID0 array, then restore your backup onto the new array.
November 11th, 2008, 06:20 PM
Thank you. Midknyte. I do computationally intensive app development. I copy my apps to memory sticks twice daily and take that from office to home and back next morning because I also work at home. I save my Sql DBs at a storage device, also I am considering a network storage instead of WD MyBook 500GB Drive.
I am encouraged that it is doable. I don't understand the technicalities though. How can I create a new array? I did realize that I cannot change RAID1 into RAD0 in a simple manner. I foresaw the total destruction of data.
Would it work if created a clone of the entire disk and then wrote it back? I have my own software ttat will do it. The second HDD contains just the system image I guess. Can I use that also for restoration or it is ridiculous?
November 11th, 2008, 06:24 PM
Also I am thinking about installing an extra HDD (there are two extra bays) and setting up an OS on it (Vista) and from there I can do backup of other drives and subsequent restore. Does it majke sense?
What kind of performance improvement will I get from the change? 50%? 75%?
November 11th, 2008, 06:34 PM
RAID0 has a much higher latency than standalone drives, or even RAID1. As such, the effective performance isn't double. Sometimes, depending on what it is you're doing, there may be no noticeable performance improvement at all. RAID0 works best, when dealing with very large files and media.
I think it's important to be aware of the risks involved with RAID0 though. There is an increased risk of array, or drive failure resulting in complete and total data loss on the RAID0 array. I've experienced this, as I'm sure many other members also have. RAID0 is fun to play around with, but it's like skating on thin ice. I only deal with RAID1, RAID5 or RAID6 (for corporate) these days.
Echoing what Midknyte has already said, to set up RAID0, you would first need to backup all data off your current RAID1 array before breaking the array and recreating it anew as RAID0.
If you don't intend on reformatting afterwards, then you need to use imaging (cloning) software to take a snapshot of the drive as your backup. Something like Acronis is good for this. I am concerned though that there may be a chance your operating system (can I assume it's Windows?) may have issues with the change in the nature of the hard drive controller. It would still be the same controller, but switching it from RAID1 to RAID0 may cause a conflict. Windows is especially finicky when it comes to changes in the hard drive controller for the system drive.
November 11th, 2008, 06:39 PM
Ha, I didn't see your response because you got it in just before me
Assuming the RAID controller is built into the motherboard, it should be possible to enter a RAID configuration menu in the initial stages of the computer booting. Which key you need to press depends on the controller type. I'd imagine there's a Dell logo hiding all the typical initial boot info?
November 11th, 2008, 06:58 PM
Thanks Bink. Don't recall the logo. Do it every so often but seldom pay attention. Most likely F2 I would guess. You mean the system configuration, BIOS, etc? Must be F2.
I've never looked into BIOS at this machine, though. As long as it is problem free I am not curious. You've made me nervous for a good cause. Perhaps I should forget about it. I don't realy deal with very large files. Actually I do (various DataTables) but I can schedule that work for off hours. Especially if I don't get a jump in performance or it is questionable perhaps I should stay out of trouble.
It makes sense to me now. I recall that RAID 0 probably was not an option on menu at the time ordered it.
My OS is always Vista Ultimate all around on all machines.
Thanks a lot.
November 11th, 2008, 09:20 PM
The RAID configuration is separate to the main motherboard BIOS configuration. The RAID configuration is usually accessible on the next screen where the RAID controller is initialised.
November 11th, 2008, 11:49 PM
I've never seen a motherboard that had RAID1 and didn't have RAID0.
The RAID config screen might be something like ctrl+a or ctrl+i, AFTER the initial bios setup message.
Either way, you need a backup plan.
That is NOT a real backup. If your hard drives die, you wouldn't be able to restore the complete OS and apps. Acronis TrueImage is my pick, but you can also try Paragon since it's free. http://www.drive-backup.com/
I copy my apps to memory sticks twice daily and take that from office to home and back next morning
November 12th, 2008, 12:50 PM
Thank you Brink and MidKnyte. My situation with backups is different. I am an MSDN Pro subscriber and I have DVDs with OS that I can install on my machines in limited numbers. I can also download Vista with SP1 and many other software. I've reinstalled Vista many times in the past and MS always endorsed it as genuine and upgrades were done.
The real issue for me is not so much Vista reinstall but many other relevant MS Kits I use in abundance. Reinstalling them takes time. But the thing is I've found that my hardware is so reliable that the chance of a HDD crash is miniscule. As a matter of fact I had it only once perhaps 18 years ago. All my previous reinstalls were due to Software problems. For instance, now I cannot upgrade Sql Server to 2008 version on one of my machines because of a stupid bug I cannot figure out how to fix. Something is lodged in the Registry and I have no idea where it is. It could be one of 3-rd party ghosts I deleted.
I don't use Acronis. I have my own app that does exactly that: clone entire disk to another disk. I developed it myself.
I appreciate you answers. It's been educational. i will store this information in my archive. I've decided not to mess with it. I will lose time, increase complexity and perhaps gain very little. I don't do media or movies. My app is all number crunching, donwloading stock quotes from servers and storing information in Sql Server. I can find a way to optimize process with rational software configurations.
Last edited by alexBB; November 12th, 2008 at 12:54 PM.
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