RAID question.
 

I have one HD installed right now, but I have a second one I'd like to add to it. I want to configure them in a RAID-0 (That's stripe, right?).

I recall reading somewhere that when you set up a RAID-0 that both hard drives will need to be formatted. Is this true? And if not, how do I get around it?

I'm probably just going to have to back up my shit... and a reformat is probably about due... I'm just lazy, and I'd rather not do it if I can avoid it.

Thanks.

I'm pretty sure if you're setting up a raid array on two harddrives you need to format both of them before you can use them in raid. Also i believe you need to have the exact same size harddrives as well. I'm not sure if it has to be the same manufacturer, but hopefully somone will reply with some more info.

EXACTLY what he said. I'm not sure about the same manufactuer, but you do need to format and they do have to be exact same size.

they few raid array's i have set up the disks do not need to be the same size, what it will do though is double the size of the smallest drive.... thus a 60 and 80 gig drive will result in a 120 gig array...

Hopefully you are setting up a hardware controled array, it is the only way you will see increased preformance.... windows 2k xp will allow software raid but it is NOT worth the trouble....

It will wipe all drives being inserted into the array, so you better have some kind of media to back up to for a few hours..... I recomend getting or borrowing a usb2 external drive to use for backups....

My buddy just did a RAID 0 Setup and increased his performance by 80 points on PC Performance online test. No other hardware added except changing to Raid 0.
Your best bet for a hassle free Raid Setup is identical drives. If you do the setup on IDE, put one drive as master on one chain, and the second drive as master on chain 2. If you do it with SATA, no worries it is automatically on different chains.

Er.

For the first three people that replied: For RAID-1 the two drives need to be the same size. That's because all the data is copied onto BOTH drives. I'm not talking about RAID-1. I'm talking about RAID-0, which will just increase my data capacity. The two drives do NOT have to be the same size (at least on my motherboard... maybe lower end ones don't handle it properly?).

theburner: Did your friend format his drives? I imagine he had to, but there's a slight hope that I can get around it...

they need to be blank, or at least they will be once they are striped to gether.

you need a place to dump your data first.

The drives don't have to be the same size for Raid0 or Raid1 MooseMan, but you'll only use the drive space on the bigger drive up to the size of the smallest drive. That's because the data is striped across the drives for Raid0, and mirrored for Raid1.

What you might be talking about is JBOD (Just a bunch of disks!), another feature used by many inexpensive RAID controllers that simply spans drives of any size together into one large logical drive.

I'm wary to do either Raid0 or JBOD for anything that I want to keep, like pictures, documents, music or videos. If you think you're sad when one hard drive fails, multiply that sadness by the number of disks in your Raid0 or JBOD array, because when one disk kicks the bucket, all your data goes bye-bye.

Of course, there are specialized applications that can benefit from Raid0's speed and capacity advantages, like audio/video editing or other disk-swapping intensive applications, but I wouldn't recommend it for most people. Since the original poster seems to be worried about backing up the data on the first drive, I'm assuming it's not data that he cares to lose...

You can read all about it at sites like www.StorageReview.com.

Mooseman.. Yes, you do need to format the disks. If you have already had one or both of the disks in use in your system they will already have the NTFS (hopefully not FAT32) set up, so theoretically you don't need to format. However, for a nice clean, fresh install I would recommend it.
Ack32 is correct, your drives theoretically don't need to be the same size. However, in order to maximize your performance and utilize the full capacity of all disks, it is recommended that you use identical disks (or at least disks of the same capacity).
I am going to be blowing away my system to set up a RAID 0 in a week or two. I am just making 100% sure all of my data is backed up before I do it.
Ack32 is also correct about RAID 0 not being a true form of Data Protection, all it really does is speed up your data transfer (2 pipes instead of one). Raid 1 is slower than RAID 0, but does provide COMPLETE data protection.
Personally, if I had the cash and the room in my system I would run a RAID 0+1 in my system. However, buying that 3rd disk just isn't in the cards right now.
Raid 0 -> Pure Striping. No Data Protection. FAST
Raid 1 -> Mirroring. 100% Data Protection, Slow
Raid 0+1 -> Mirroring with Striping: 100% Data Protection. Best form for home user.
Raid 3 -> Striping with Parity Disk: Complete Data Protection, requires 3 Disks. Amount of usable space is the number of drives minus one.
Raid 5 -> Striping with Parity striped across all disks: Complete Data protection, required minimum 3 disks. One drive can fail and not effect the integrity of the data. Best suited for HEAVY read applications.

Hope this helps.

You can't get around having to format the disk. Sorry.

If you use a RAID 0, it doesn't matter how large the disks are. If you use a RAID 1, you can only use as much space as the smallest of the two drives provides.

yes it does, you will only use the smaller hard drive to base the total size, if you were to stripe a 40 gig and a 20 gig, you would get a 40 gig drive not a 60.

if you spanned the drives, you would get a 60 gig drive. but no redundancy and no boost in speed.

Mooseman.. Dilbert is correct.. 100% you have to have identical capacities in order to use all of the drives in Raid 0.

see http://www.pcguide.com/ref/hdd/perf/...eLevel0-c.html or the following

please not the red selection


RAID Level 0

Common Name(s): RAID 0. (Note that the term "RAID 0" is sometimes used to mean not only the conventional striping technique described here but also other "non-redundant" ways of setting up disk arrays. Sometimes it is (probably incorrectly) used just to describe a collection of disks that doesn't use redundancy.)

Technique(s) Used: Striping (without parity)

Description: The simplest RAID level, RAID 0 should really be called "AID", since it involves no redundancy. Files are broken into stripes of a size dictated by the user-defined stripe size of the array, and stripes are sent to each disk in the array. Giving up redundancy allows this RAID level the best overall performance characteristics of the single RAID levels, especially for its cost. For this reason, it is becoming increasingly popular by performance-seekers, especially in the lower end of the marketplace.



This illustration shows how files of different sizes are distributed between the
drives on a four-disk, 16 kiB stripe size RAID 0 array. The red file is 4 kiB in
size; the blue is 20 kiB; the green is 100 kiB; and the magenta is 500 kiB.
They are shown drawn to scale to illustrate how much space they take
up in relative terms in the array--one vertical pixel represents 1 kiB.
(To see the impact that increasing or decreasing stripe size has on the
way the data is stored in the array, see the 4 kiB and 64 kiB stripe size
versions of this illustration on the page discussing stripe size issues.)


Controller Requirements: Supported by all hardware controllers, both SCSI and IDE/ATA, and also most software RAID solutions.

Hard Disk Requirements: Minimum of two hard disks (some may support one drive, the point of which escapes me); maximum set by controller. Any type may be used, but they should be of identical type and size for best performance and to eliminate "waste".

Array Capacity: (Size of Smallest Drive * Number of Drives).

Storage Efficiency: 100% if identical drives are used.

Fault Tolerance: None. Failure of any drive results in loss of all data, short of specialized data recovery.

Availability: Lowest of any RAID level. Lack of fault tolerance means no rapid recovery from failures. Failure of any drive results in array being lost and immediate downtime until array can be rebuilt and data restored from backup.

Degradation and Rebuilding: Not applicable.

Random Read Performance: Very good; better if using larger stripe sizes if the controller supports independent reads to different disks in the array.

Random Write Performance: Very good; again, best if using a larger stripe size and a controller supporting independent writes.

Sequential Read Performance: Very good to excellent.

Sequential Write Performance: Very good.

Cost: Lowest of all RAID levels.

Special Considerations: Using a RAID 0 array without backing up any changes made to its data at least daily is a loud statement that that data is not important to you.

Recommended Uses: Non-critical data (or data that changes infrequently and is backed up regularly) requiring high speed, particularly write speed, and low cost of implementation. Audio and video streaming and editing; web servers; graphic design; high-end gaming or hobbyist systems; temporary or "scratch" disks on larger machines.

In my opinion, it is not worth it in your situation to have a RAID 0 set up. I don't believe the slight increase in performance ever warrants the time and trouble involved. Not to mention that in the case where one drive fails, you will lose all of you data. In JBOD, you will retain the data on the healthy drives if one in the array fails. It will be time-consuming to recover, but doable. I like RAID 5 for the performance/security balance. You need at least 3 drives, however, and you lose one drive's worth of space for redundant info. Back when I had more money, I was looking at a couple of 5-in-3 drive cages, but now I'm poor :(

http://www.acnc.com/04_00.html
is a pretty decent site to learn all this stuff.