What exactly *is* RAID? (Don't laugh!)

J

JYeager11

Gawd
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Nov 15, 2006
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OK guys, don't laugh, but I don't know SQUAT about RAID.

My motherboard (A8N-SLI Deluxe) does RAID, but I've been ignoring it since Day 1 simply because anything I don't already know about scares me. ;)

Now, installing this 3rd drive on my system today, I noticed the slot configuration on my MB. I've got 4 SATA slots (1,2,3,4), and 4 SATA-RAID slots (1,2,3,4). And my drives are currently installed in the normal SATA slots (1,2,3).

What is RAID? What would I gain by putting the drives in THOSE slots instead? I do remember disabling the Silicon RAID check at boot-up in the BIOS because it was slowing down the bootup process by 15 full seconds... so I guess I'd have to re-enable that... but WHY? What would those 15 extra seconds of scan time during the bootup give me in return?

thanks.
 
This topic has been discussed numerous times here on the forum, let your fingers do the walking on this one. Having said that, he is a a brief overview of RAID.
It depends on what RAID you are doing, but you need to have all disks the same size;
RAID 0 (not true raid) basically takes 2 or more disks and makes them appear as one large drive, however the reason it is not true raid is because if one of those disks die, then the whole array is dead.
RAID 1 is a mirror option, you have two disks and whatever you do to the disk, it copies it to the other disk, good for server OS installation, so when 1 drive dies, the other one has everything exact so its merely pulling out that damaged disk and it still works without a hitch.
RAID 5 is where you take 3 or more disks and they appear as 1 large array, however if 1 drive dies, the array still works, it is degraded but it can still function till the disk is replaced.
Then there are more options, 10, 50, etc but if you need more detailed information look here.
 
Sparkyy said:
This topic has been discussed numerous times here on the forum, let your fingers do the walking on this one. Having said that, he is a a brief overview of RAID.
It depends on what RAID you are doing, but you need to have all disks the same size;
Click to expand...

Considering none of them are, I guess my exploring for the day stops there. LOL

Thanks, Spark.
 
Heh, no problem, just hope that answers some of your questions, if you have more then please feel free to ask away. :D
 
RAID0 = Stripe..Basically data is striped across 2 or more disk. Offer the best I/O performance.

RAID1 = Mirrored Disk. data two copies the data are stored on different disks. In the event of disk failiure, the data can still be accessed on the second copy.
Decent read performance, but suffers from write penalty.

RAID5 = Stripe with distributed parity information stored on a different disk. Requires at least 3 disk. In the event a disk failure. The remaining stripe data and parity information will allow for the recovery of lost in the failed disk.
Decent read performance, but extremely poor write performance...Zero performance in the event of singled failed disk during mirror rebuild.

RAID6 = Stripe with double distribueted parity. Same as above but 2 copies of parity data is stored. Same poor write performance....but faster rebuild times....

RAID10 = Mirrored Stripe..... Basically a striped array..by each stripe is mirrored...

Typically if you want acceptable write performance with RAID5, RAID6, RAID10.. you will like to use a dedicated RAID card which can. a.) offload parity calculation, b.) Can perform write caching to mask the write penaties of writing to multiple disk......However, with write caching, your array will be vunerable to data loss in the event of power failure and all cached write that are not written to disk yet. will be lost....Therefore
you have to get the backup battery for the cache... :)
 
i have the same MB and i was wondering if i could put 2 250gb hdds in raid0 on the raid controller and 2 other hdds on the regular controller?
 
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