Originally Posted by goros
Consider then, that some people suck at backing up their systems and that they don't take the time to do it right. They also don't want to invest the time into re-ripping all their media from the original sources if something happens to their system, and they don't want to pay for offsite line data backup.
Assuming they don't install their OS or programs to a RAID drive that they store media on, viruses and the like should have a limited impact on the media they place there. Also, media files should be write protected.
RAID offers you a way to suffer a hard disk failure inside your computer without losing the media on it that array. For some people, losing a hard drive would lose their family home videos, pictures, and other important files. Unless they back up every day, they could potentially lose SOMETHING between backups that may not be able to be recovered, ever. RAID offers the ability to maintain those files in case a crappy, $99 green hard drive shits the bed 3 years and a day after it's installed.
You don't gain data integrity backing up regularly to another hard drive anyway - all you do is copy the corrupted data from one drive to the next as part of "backing up". (the same as raid, essentially) The only way to guarantee data integrity would be to immediately (as soon after its initial write to the disk) back up or image the data to a one time write optical disc like a bd-r and to archive it someplace safe, to restore the data in all those folders in case of a failure.
It's totally worth using RAID if it's used correctly and realistically. It serves one purpose (2 if you count RAID0). It insulates you against data loss in case of a disk failure without making a backup. It's only as good as the quality of the data on the array, but it usually suffices.
And no one answered my questions about RAID6 yet.
So setting up an automatic backup schedule is too much trouble but setting up and properly managing a RAID isn't? Nonsense.
And because people SHOULD be worried about "their family home videos, pictures, and other important files" which is why they need to back them up. Putting them on a RAID doesn't protect them and telling folks it does is a serious disservice.
The difference is that you aren't backing up in real time. Most of the time your failure, infection, or corruption will manifest itself before you back it up and thus will not be replicated on the backup set. And ideally you should have both short term (like daily) backups and longer spaced (like weekly) back up sets so your problem doesn't arise. But if your only approach is to replicate it in real time on a RAID you have no chance at all of preserving a clean data set. Yes, you DO gain data integrity by backing up regularly, and any IT pro would tell you that. Your claim to the contrary is simply untrue.
And as to RAID 6, the reason for this is to have continued fault tolerance during the period from the failure of a disk until the replacement of a disk. In a single parity RAID, the array is essentially the same as a RAID 0 during this period and thus is susceptable to catastrophic failure if a second disk fails. But why in the world do you need this at home? If a disk fails, just shut array down until you can replace the bad drive. You don't need 24/7 uptime for a video server, and you should have a backup anyhow.
This "I have a RAID, my data is safe" is a myth. There seem to be a lot of people here with a false sense of security.