RAID Capacity WRONG!

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Maurice The Odd

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Dec 19, 2013
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I got the following drives connected in RAID5/64KB:
2x290G
1x480G

I tried to raid all of them but I get only 590GB of storage disk, what the..? isn't it supposed to be 1TB ?
When I tried RAID only on the 2x290G I got a storage of 290G only, what the hell is wrong?
 
Solution
rgd1101



if you are using windows "Dynamic Disks"
http://msdn.microsoft.com/en-us/library/windows/desktop/aa363785%28v=vs.85%29.aspx
http://technet.microsoft.com/en-us/library/cc731274.aspx
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ronintexas

ronintexas

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Dec 10, 2012
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First, what are you trying to accomplish by putting the drives in a RAID array?

A word of warning - drives in RAID for desktop usage are not recommended - here is why. 1 drive means that when a drive fails, you are out of luck. With 2 drives in RAID, you are TWICE as likely to have a failure - with 3 drives, three times as likely....etc.

Unless you absolutely have to have a RAID array for a program (i.e. Windows Media Center requires a single drive for recordings - and with copy protection from the manufacturers, you can't always move the files). Most every program out there seamlessly will integrate into multiple hard drives.

RAID for use in specific applications to gain a single drive, or for high performance/high reliability application servers (i.e. database servers), where money is no object for reliability, RAID gives big gains. The RAID servers I have at work have 25% of the total drives in the array sitting in a cabinet, waiting for a failure. RAID 10 (mirrored/striped) gives the security of being up 24/7, and increases the size of the drive I can work with.

The cost is 2.5X (because of mirroring and spare drives). 10 15k SAS drives at 300GB gives me a 1.5TB array, mirrored and striped. In a failure, I replace a single drive, and it usually takes 4-6 hours to rebuild (system performance slows, but no down time). There is also a $500 controller to increase the speed.

With all that said, backups are the most important part of the day.
 
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USAFRet

USAFRet

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Mar 16, 2013
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That sounds about exactly right.

I tried to raid all of them but I get only 590GB of storage disk, what the..? isn't it supposed to be 1TB ?
Click to expand...
RAID 5 capacity is not Drive1 + Drive2 + Drive 3. The actual capacity is actually about 67%. Add to that you have different size drives. Only 290 from the 480 drive will be used.

290+290+290 = 870GB. * 0.67 = 582GB.

When I tried RAID only on the 2x290G I got a storage of 290G only, what the hell is wrong?
Click to expand...

For RAIDing the 2 x 290's, I assume you meant RAID 1. Mirrored. So you only get the capacity of one drive, whichever is smallest.


Read more on RAID and capacity here: http://en.wikipedia.org/wiki/RAID#RAID_5

May I ask the purpose behind this RAID setup?
 
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M

Maurice The Odd

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Dec 19, 2013
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The computer was RAID when I bought it for a PC center where I live, it was configured as RAID at first place because it was a part of the server they had there.
The RAID was working fine with no failures at all for 3 years now, and I bought a new PC with an SSD. Windows is installed on the SSD while I want another big drive to place my stuff in.
So, is there any way I can get the 3 drives working together for 1TB ? (I think if it was working for 3 years without any problem, it will work great with my new specs).
 
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rgd1101

rgd1101

Don't
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Nov 7, 2011
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if you are using windows "Dynamic Disks"
http://msdn.microsoft.com/en-us/library/windows/desktop/aa363785%28v=vs.85%29.aspx
http://technet.microsoft.com/en-us/library/cc731274.aspx
 
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