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What is RAID? I hear alot about it.. Is it combining a bunch of old low-capacity drives to use as a single volume?
 

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Which one? <img src="/images/smilies/tongue.gif" border="0" alt="" title="Stick Out Tongue" class="inlineimg" /><br />
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The one you are talking about is JBOD. Some people call it a RAID....but some people don't. It is...but its not.... <img src="/images/smilies/tongue.gif" border="0" alt="" title="Stick Out Tongue" class="inlineimg" /><br />
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<a href="http://en.wikipedia.org/wiki/RAID" target="_blank">http://en.wikipedia.org/wiki/RAID</a><br />
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RAID 0-<br />
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A RAID 0 (also known as a stripe set or striped volume) splits data evenly across two or more disks with no parity information for redundancy. It is important to note that RAID 0 was not one of the original RAID levels, and is not redundant. RAID 0 is normally used to increase performance, although it can also be used as a way to create a small number of large virtual disks out of a large number of small physical ones. A RAID 0 can be created with disks of differing sizes, but the storage space added to the array by each disk is limited to the size of the smallest disk—for example, if a 120 GB disk is striped together with a 100 GB disk, the size of the array will be 200 GB (i.e. 2 times the size of the smallest: 100GB). Although RAID 0 was not specified in the original RAID paper, an idealized implementation of RAID 0 would split I/O operations into equal-sized blocks and spread them evenly across two disks. RAID 0 implementations with more than two disks are also possible, however the reliability of a given RAID 0 set is equal to the average reliability of each disk divided by the number of disks in the set. That is, reliability (as measured by mean time to failure (MTTF) or mean time between failures (MTBF) is roughly inversely proportional to the number of members—so a set of two disks is roughly half as reliable as a single disk. The reason for this is that the file system is distributed across all disks. When a drive fails the file system cannot cope with such a large loss of data and coherency since the data is "striped" across all drives. Data can be recovered using special tools. However, it will be incomplete and most likely corrupt.

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</div>JBOD-<br />
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Although a concatenation of disks (also called JBOD, or "Just a Bunch Of Disks") is not one of the numbered RAID levels, it is a popular method for combining multiple physical disk drives into a single virtual one. As the name implies, disks are merely concatenated together, end to beginning, so they appear to be a single large disk.

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</div>RAID 1-<br />
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A RAID 1 creates an exact copy (or mirror) of a set of data on two or more disks. This is useful when read performance is more important than data capacity. Such an array can only be as big as the smallest member disk. A classic RAID 1 mirrored pair contains two disks, which increases reliability exponentially over a single disk. Since each member contains a complete copy of the data, and can be addressed independently, ordinary wear-and-tear reliability is raised by the power of the number of self-contained copies. For example, consider a RAID 1 with two identical models of a disk drive with a weekly probability of failure of 1:500. Assuming defective drives are replaced weekly, the installation would carry a 1:250,000 probability of failure for a given week. That is, the likelihood that the RAID array is down due to mechanical failure during any given week is the product of the likelihoods of failure of both drives.

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</div>RAID 5-<br />
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A RAID 5 uses block-level striping with parity data distributed across all member disks. RAID 5 has achieved popularity due to its low cost of redundancy. Generally, RAID 5 is implemented with hardware support for parity calculations.

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</div>By far the most common are RAID 0 and RAID 1. You can use both at the same time as well, but you need 4 drives minimum for that.<br />
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JBOD isn't that well used, since most people with a lot of hard drives just use one for Windows, one for media, one for the page file, yada yada.<br />
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RAID 5 isn't used much either. Don't think anyone here has it. <img src="/images/smilies/thinking.gif" border="0" alt="" title="Thinking" class="inlineimg" /><br />
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Chozart also has a FAQ on it, in his sig- and knowing him; he'll be here soon. <img src="/images/smilies/tongue.gif" border="0" alt="" title="Stick Out Tongue" class="inlineimg" /><br />
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(btw, there are more, but I just posted the most common)
 

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Originally Posted by <strong>LyokoHaCk</strong>

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<div style="font-style:italic">What is RAID? I hear alot about it.. Is it combining a bunch of old low-capacity drives to use as a single volume?</div>

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</div>Pretty much its combining HDDs and accessing them simultaneously. You need a Raid Controller, either onboard or purchase. Most people go for the RAID 0 configuration because that gives you the best speed. The other RAID configurations after 0 are not as fast but act as backup if one of your HDDs go down.<br />
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I just went RAID0 with Seagates new 320G SATA II Barracudas with new Perpendicular Technology:<br />
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<a href="http://www.newegg.com/product/product.asp?item=N82E16822148140" target="_blank">http://www.newegg.com/product/produc...82E16822148140</a><br />
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They were about $95 a pop with free shipping from newegg right now. So for $200 I got 640 gigs that run at blazing speeds - and when I mean blazing I mean BLAZING <img src="/images/smilies/eek.gif" border="0" alt="" title="EEK!" class="inlineimg" /> speeds.<br />
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Raid 0 simply stripes both your HDDs so that when you perform disc access you're really accessing both HDDs at once. So you can see why that would be quicker in most cases.<br />
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Generally if you go Raid0 you spend less and get superior performance/cost ratio. The only drawback is you have to spend more time setting it up, and you have more voltage draw and temp issues - but if you're an O'clocker then that's what you live for. <img src="/images/smilies/biggrin.gif" border="0" alt="" title="Big Grin" class="inlineimg" /> And also - you now have two HDDs instead of one you are depending on not breaking down - since if one goes out you lose all your data. So you want to have some kind of backup system - usually a large slow external drive to backup your most critical data.
 

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RAID is a way of splitting or mirroring data on a set of discs to add performance/security or both.<br />
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RAID - 0 = strictly striping. It takes the data and splits it between as many drives as are in the array. You lose one, you are out of luck.<br />
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RAID - 1 = Stricly mirroring. It takes the data and writes it the same way to ALL of the discs in the array. You lose one, and the other ones are all useable.<br />
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There's more, but those are what most overclockers are used to.
 

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Don't Forget RAID 0+1. Mirroring AND striping <img alt="" class="inlineimg" src="/images/smilies/smile.gif" style="border:0px solid;" title="Smile"><br><br>
Heres a link to Chozarts RAID FAQ: <a href="http://www.overclock.net/faqs/90757-opinion-raid-performance-comparison-should-i.html" target="_blank">LINKY</a>
 

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Discussion Starter #6
Kinda like SLI? (In a Hard drive kind of way <img src="/images/smilies/tongue.gif" border="0" alt="" title="Stick Out Tongue" class="inlineimg" /> )
 

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Originally Posted by <strong>LyokoHaCk</strong>

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<div style="font-style:italic">Kinda like SLI? (In a Hard drive kind of way <img src="/images/smilies/tongue.gif" border="0" alt="" title="Stick Out Tongue" class="inlineimg" /> )</div>

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</div>YIP!
 

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Discussion Starter #8
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Originally Posted by <strong>jamenta</strong>

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<div style="font-style:italic">Pretty much its combining HDDs and accessing them simultaneously. You need a Raid Controller, either onboard or purchase. Most people go for the RAID 0 configuration because that gives you the best speed. The other RAID configurations after 0 are not as fast but act as backup if one of your HDDs go down.<br />
<br />
I just went RAID0 with Seagates new 320G SATA II Barracudas with new Perpendicular Technology:<br />
<br />
<a href="http://www.newegg.com/product/product.asp?item=N82E16822148140" target="_blank">http://www.newegg.com/product/produc...82E16822148140</a><br />
<br />
They were about $95 a pop with free shipping from newegg right now. So for $200 I got 640 gigs that run at blazing speeds - and when I mean blazing I mean BLAZING <img src="/images/smilies/eek.gif" border="0" alt="" title="EEK!" class="inlineimg" /> speeds.<br />
<br />
Raid 0 simply stripes both your HDDs so that when you perform disc access you're really accessing both HDDs at once. So you can see why that would be quicker in most cases.<br />
<br />
Generally if you go Raid0 you spend less and get superior performance/cost ratio. The only drawback is you have to spend more time setting it up, and you have more voltage draw and temp issues - but if you're an O'clocker then that's what you live for. <img src="/images/smilies/biggrin.gif" border="0" alt="" title="Big Grin" class="inlineimg" /> And also - you now have two HDDs instead of one you are depending on not breaking down - since if one goes out you lose all your data. So you want to have some kind of backup system - usually a large slow external drive to backup your most critical data.</div>

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Then again... That seems a bit risky!<br />
<img src="/images/smilies/cigar.gif" border="0" alt="" title="Cigar" class="inlineimg" /><br />
<img src="/images/smilies/frown.gif" border="0" alt="" title="Frown" class="inlineimg" />
 

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Not really. HDDs are pretty dependable and will last a number of years. Most PC'rs don't even back-up the one hard drive they have. I would say your risk is relatively low and with an external HDD back-up its almost none at all. That is of course, if you simply do RAID 0. With Raid 0+1 or other RAID configs - you also have really have next to no risk.
 
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