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RAID Options - Racking Brain, please help

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February 26, 2007 4:48:54 PM

Current setup: Two 150gb raptor drives. No RAID. I use a program called Casper XP and just copy C to D once a week. This is actually good because when I screw up the software on my C drive, I can just switch the sata cables and D becomes C.

So with this new computer I want to build, I wanted to get it going faster with a RAID 0 setup, but is it possible to do a RAID 0 and then have another drive that I can use to back up once a week? From what I am reading I dont think its possible because RAID 0 is not a complete copy on either drive but a complete copy combined? So do I have a solution?

Thanks.
February 26, 2007 6:23:15 PM

Well, if you are actually going to backup your data, then you can raid 0 the first two, then buy a separate 300GB HD to copy an image or backup to. Assuming you have an extra sata or ide port available for another drive.

RAID 0 is actually disk striping, it isn't redundant, so calling it RAID just makes people feel like they are running something fancy. If you really have to have it run that much faster, and are willing to deal with the associated chance of 100% data loss if you don't backup, then you are good to go.

But please buy a 300GB drive to backup to.

edit: btw, the driver that windows will load for your raid will be different than the driver used to boot a single hd, so I don't know how well your backup program you are currently using will fair.

Centurion
February 26, 2007 7:21:21 PM

Yes it is possible provided your "other" 3rd drive is 300GB or larger. The two 150GB raptors in RAID 0 will appear as one 300GB drive.

As mentioned there is NO redundancy in RAID 0. If one drive in the RAID 0 array fails, everything is essentially lost. The same is true if the controller fails. A weekly backup plan to a NON RAID drive is a good idea.

Personally, for weekly backups or longer I prefer an external HD because it is not on all the time, wearing things out, drawing power, and adding heat. It is also less susceptible to any power surges, or a bad MB or power supply. However in this case you would need to restore to a working drive unless it was an eSATA drive.
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February 26, 2007 7:44:18 PM

I am curious about this RAID 0 plus backup option. Lets assume that one of disks in RAID 0 crashes. What I am left with is a 300gb drive with a backup of the RAID 0 array (I also assume that this backup is a ghost image). Can I simply switch some cables around and my backup drive can become my operating drive? Will the OS and bios allow me to all of the sudden make this 300gb drive my :C drive? If so, that is excellent.

Can you explain more about your last sentence, "However in this case you would need to restore to a working drive unless it was an eSATA drive."

If I went with an external backup hard drive could I not operate from it if needed? What would be the procedure?
February 26, 2007 8:36:33 PM

It would be far easier to just change the boot options in the BIOS with your current setup. With a RAID array and another drive it would be the only way to make it work.
February 26, 2007 9:12:09 PM

If I went with an eSATA drive, would the drive be in the bios? I don't know. I've never had one. Not sure if it is just plug and play or what? Also, in looking at the bios on my computer now, my boot options consist of hard drives, cdrom, or floppy, but it doesn't give me the option to decide which hard drive to boot from.

Bottom line, If I use an eSATA drive with a RAID 0 configuration for a total of 3 drives, is it sound? A weekly backup would more then suffice for my needs. I just wonder what you do if you along the way, the RAID 0 goes down and you begin booting from the eSATA drive, how do you ever get your RAID 0 set up again?
February 26, 2007 11:05:13 PM

It's a perfectly viable setup, you just have to learn how to create the hardware raid array and set it's boot priority.

The only difference real between eSATA and internal SATA is the plug and some software settings in the OS to make it hot-swap compatible (so you don't loose data when hot unpluging it). Your computer basically doesn't know the difference. Once you figure out how to make your system boot from your raid array in the first place you will have the answer to all of your questions. Basically you make your system boot from your raid array, you copy the data to the backup drive, if the system on your raid array stops working you just stop booting from it until you get it up and running again then copy the data back and boot from it again. It's a setting in your BIOS and/or your SATA RAID controller (which may or may not be a seperate module and may or may not be a seperate card). The exact instructions how how to do it would be specific to your system.

To make it go as smoothly you will want the raid array and the backup drive be connected to the same raid controller so there is no change in drivers when you switch between them and all you have to do is change the boot disk in the software menue of the raid controller. Unplugging the cables won't work as the controller will be looking for the array. Swaping the cables around would probably cause data loss.

Also, your backup drive doesn't need to be 300gb per say. It just needs to be bigger than the amount of data you actually have.

Oh, you might have problems getting the ghosting software to work with the raid array. It should work, just warning you though.

It is very decent setup for a high-performance raid-0 array with a nearline backup. It won't be quite as simple as the setup you have now, but it will be faster and more cost effective (using a 150g raptor purely as a backup drive is insanity) and I encourage you to pursue getting it set up but I think you'll need to read some manuals and ask more specific questions to get any help on the boards.
March 5, 2007 4:26:51 PM

Sorry for the delay I was out of town the rest of the week.

Quote:
I am curious about this RAID 0 plus backup option. Lets assume that one of disks in RAID 0 crashes. What I am left with is a 300gb drive with a backup of the RAID 0 array (I also assume that this backup is a ghost image). Can I simply switch some cables around and my backup drive can become my operating drive? Will the OS and bios allow me to all of the sudden make this 300gb drive my :C drive? If so, that is excellent.


If the backup drive is an identical copy, then yes, you can make the backup drive your operating drive. If it is a backup that needs to be "restored" then you would have restore it to another drive. This is what many people use external USB drives for. This type of backup also compresses data, allows incremental backups, and various restore points etc.

Quote:
Can you explain more about your last sentence, "However in this case you would need to restore to a working drive unless it was an eSATA drive."


An eSATA drive is an external SATA drive. It is essentially as fast as a regular SATA drive, and since it is an external drive, it is easy to plug it in only for backups vs. an internal SATA drive. It should also be an easy BIOS change to boot from that drive, or it may even be automatic if the RAID array fails.

Quote:
If I went with an external backup hard drive could I not operate from it if needed? What would be the procedure?


If the MB supports it you could run off the USB drive, but eSATA would be faster.
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