RAID with Dual Boot

Question

I'm completely new to the world of RAID. I think I want to use RAID 5 with three 1 TB drives to backup all my documents, pictures, music, projects, etc. I use both Ubuntu Linux 10.04 and Windows 7. I've had good luck with accessing NTFS in linux in the past, but Windows can't see ext3 or ext4.

What is a good solution using RAID for documents, pictures, music and projects (hopefully accessible by both operating systems) and still dual boot? I was thinking I'd have a separate drive for each OS and NTFS for the RAID hard drives. And to add on to that, if possible, mirror each OS drive. without mirroring, I'm up to 5 drives. With mirroring, I'm up to 7. I only have 6 SATA slots, but I assume I could use a card to have support for 8.

I'm not sure if this is an ambitious setup or typical for some. Thanks for any advice.

EDIT: Sorry I wasn't clear. I'm backing up my docs, music, etc. from two other computers to this computer. I'd like that backed up data to have some redundancy. Hence my question about RAID.

Answer 1

If you use Windows Software RAID, it will most likely only be visible to Windows and cause you trouble in the long run.

If I was you, look for RAID drivers for your motherboard then set it up through the hardware - this is by far the best sort of RAID you can do.

As far as your operating system is concerned, it is running on a regular hard disk is unaware of the RAID that is going on at the hardware level (except if you have a driver/smart program that alerts it - but still, it should work the same as a regular hard drive).

You can install multiple operating systems or do pretty much anything you can with a regular hard drive and it is much simpler in the long run. (Installing may require an additional driver - you can probably find from your motherboard manufacturer).

Hardware RAID has many benefits (usually) including being faster / more reliable, higher compatibility, and sometimes hot rebuild (although some software RAID also support this).

At the same time, just remember the golder rule - RAID IS NOT BACKUP. When you consider how many hard drives you are going to be using for the once in 2-3 year disaster, you may be much better off simply buying a stack of CDs or a nas/subscribing for offsite storage and taking regular backups.

Answer 2

The only RAID that can be considered anything close to a "backup" is RAID 1, because both hard drives are mirrored (exactly identical). This isn't actually a backup, per se, but allows for a redundant storage of data. If a user deletes a file, it is instantly deleted from both drives (and therefor this does not provide a backup to restore the file.) The reason a mirror is the closest thing to a backup versus other forms of RAID is that the RAID controller is not actually required to recover files from these drives.

If your actual RAID controller dies in any other type of RAID (i.e. RAID5, RAID0, RAID10, etc.), it is unlikely that you would be able to recover the files on the drives. This is because some volume information is stored on the actual RAID controller itself.

Because of your dual booting, I assume you will be using a hardware RAID controller. This is because you'll want something that runs at the hardware level before your operating systems start, allowing you to dual boot or do other things since the RAID volume will appear as one hard drive to the software.

For more information about which RAID controller to purchase, check out this previously asked question: Which RAID controller should I use?