View Full Version : Just how touchy is RAID 0?
Tue, 25th Jan '05, 12:00pm
So, they say that if you have 2+ SATA dives hooked together in a RAID 0 array, the drives could loose data if there is a drive failure. So what does that mean?
Does that only mean that you'll loose data if the drive actually dies?
Or does that mean that mean that you'll loose everything, from Windows to that Mp3 file you just downloaded, if something so small as a power outage occurs?
I can understand that you'd loose any un-saved data if a power outage happens, but not everything on the entire drive(s)! Please tell me that you only loose any un-saved data. :rolling:
Tue, 25th Jan '05, 1:29pm
It means that all data will be unrecoverably lost if one of the drives dies. In RAID 0 the data stream is split and sent into the caches of the two drives to enhance the data transfer rate (marginally). Each drive gets half of the information. There are no redundancies, i.e. if one of the drives is stone dead, you will have lost everything.
Something as unspectacular as a power outage (which doesn't kill the hardware) will have no effect on already saved data.
I don't see the point of RAID 0, however. It isn't that fast (from all the benchmarks I've seen) and you risk losing data on two drives instead of just on one. Even if this possibility is unlikely. Up til now I haven't even had a single bad sector on any hard drive I've ever owned.
Buy yourself another drive and set up a RAID 5. ;) I guess you'll learn a lot...
Tue, 25th Jan '05, 6:50pm
Essentially with RAID 0, you are trading a performance increase (which as Darkthrone said could be a marginal increase) and a doubling of storage capacity (two disks are treated like one of twice the size) for twice the probability of data loss compared to a single disk.
Offhand, I would say the amount of data lost due to a drive failure/glitch is the same regardless of RAID 0 or not.
Tue, 25th Jan '05, 9:48pm
I see. Well, I have been thinking of RAID 5, but I'd have to buy a controller card for it...the mobo I'll be hooking it up to only supports RAID 0 and 1. :rolling:
Tue, 25th Jan '05, 9:55pm
Well, what do you want to accomplish? If this is just a desktop box for personal use, why use RAID at all?
RAID 1 is good if you don't want to do any backing-up...
Wed, 26th Jan '05, 12:16am
Try Raid 0+1 if you're concerned about losing data but still demand the speed. Of course, you'd need four identical drives....
Wed, 26th Jan '05, 8:00am
Hey! I'm not made out of money here!
And as for BTA's question, it would be a server for a house of 5+ computers...so speed and reliability are a must.
I know for a fact that the mobo that'll be used supports RAID 0 and 1...but I'm not sure about the 0/1 or 0+1 thingy that Rednik suggested. :rolling: :rolling:
Wed, 26th Jan '05, 7:51pm
Some of the newer mobos support Raid 0+1, I know mine does.
Wed, 26th Jan '05, 8:42pm
Personally, I don't see any use for anything other than Raid 1. Though it does make backup a LOT easier, especially if you're constantly updating things.
Thu, 27th Jan '05, 3:31am
Used to be, with 6 and 2GB drives, the tolerances were enormous. Not much heat, lot of room for expansion.
It's competely different with 20 and 400GB drives.
Drives these days routinely get warm to the touch. 40C. The one thing that will increase your odds of living successfully with a Raid-0 is keeping your drives cool. Personally, I use 3-in-5.25" converters. It takes up the space of two 5.25" spaces, and it holds three 3.5" hard disks and a quiet 80mm fan. Picked them up for $30 in my part of town, but I'll tell you that anything is better than nothing. I also have a couple "surplus" removable caddies that cost me $10.
You don't need nothing (or "anything" if you're north of the Mason-Dixon) fancy like an aluminium frame and a thermal pad, or watercooling. Just a simple fan blowing across it will keep temperatures down, and your reliability up. If you really wanted to make it easy, you can fit a 60x25mm fan right in front of the normal cage of most cases. You'd pull your hard disks out, stick that fan up in front of them with the label-side blowing into the case, and put your hard disks right back in. The fan won't fall over, and it won't start knocking against anything (unless the cord gets in the way; just tape it).
Nice, cool, reliable Raid-0. You can really tell the difference anytime you're working with large files. It does make a difference with games, but not as much as you might expect since they use file-compression these days. You'll notice it defragging faster.
Thu, 27th Jan '05, 11:31pm
Modern hard drives are pretty reliable anyway. It all comes down to whether you want to fork out a bit more to do another RAID version, or whether you can't afford it.
Personally, I always choose striping.
EDIT: I do not use my computer for business or money-related issues. If you do then you might not want to risk it.
[ January 31, 2005, 23:19: Message edited by: Yirimyah ]
Sat, 5th Mar '05, 5:59am
The reason why you don't see bad sectors as often as before is not because hard drives have become more reliable. It is because hidden spare sectors are put on the drives. Once a sector is declared bad a spare one takes its place, without you knowing. This happens at low level. It is just PR stunt to keep the customers happy. At least before you could use the appearance of bad sectors as a sign to change your drive.