Newbie Raid Question

[shahman]

I have a raid sata controller on my motherboard ASUS AN8-SLI Deluxe
If I hook up 3 identical HDs at RAID 5 does this mean that I don't have to back up...ever
If one disk crashes, can I just replace and the system will rebuild the data from the other disks?

 

[Abix]

As long as only *one* disk crashes at a time, yes. Also, dont forget to take into account OS crashes, virii, etc. Your data will never go corrupt from a bad hard drive as long as only one hard drive crashes at a time, but that doesnt mean you shouldnt ever backup your data to avoid losing data to a malicious virus, OS error, etc.

Also, if youre going to do a Raid5, the best thing to do in my opinion is to always keep a spare connected just in case so that if one drive fails, you can almost immedeatly(after the array is rebuilt) get back up and running.

 

[DaveSimmons]

What Abix said, plus add user error, like accidentally deleting the wrong file or folder. Plus fire, flood, power surge, power supply failure, controller failure, and theft.

Having no other data protection strategy is very foolish if you care about the data.

 

[shahman]

Thanks for the replys

So the raid 5 is raid 5 - there is no difference between raid 5 on a card and raid 5 off a motherboard chip

The OS is on a totally separate HD that will be ghosted to CD-R
I was going to do the occasional backup and deletes will be taken care of via software

 

[imported_Computer MAn]

Originally posted by: DaveSimmons
What Abix said, plus add user error, like accidentally deleting the wrong file or folder. Plus fire, flood, power surge, power supply failure, controller failure, and theft.

Having no other data protection strategy is very foolish if you care about the data.

 

[Abix]

Originally posted by: shahman
Thanks for the replys

So the raid 5 is raid 5 - there is no difference between raid 5 on a card and raid 5 off a motherboard chip

The OS is on a totally separate HD that will be ghosted to CD-R
I was going to do the occasional backup and deletes will be taken care of via software

Not precisely. RAID 5 on a motherboard chip is 99.999% software RAID. If you buy a good RAID card, it is hardware RAID. Whats the difference?

We know that in RAID 5 with three drives you have two data bits and one parity bit per segment of data. We also know that there are calculations to be done in creating that parity bit. What I assume you dont know is that in software RAID(onboard RAID chips and most cheap RAID cards) your main processor gets the task of doing those calculations while in hardware RAID the processor(s) on the card get the task of doing those calculations.

What does this mean for you? It means that if youre doing software RAID, you will see higher CPU usage as well as slower transfer rates on your array compared to hardware RAID.

 

[shahman]

Thanks for the reply.

So just to clarify. Raid off say and Nforce 4 motherboard chip will use the cpu to do parity bit calculations.
Raid off a silicon image raid controller chip may or may not do its own calculations. I will need to talk to the vendor about this.

Thanks