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You lose a 1/3 of total space on a raid 5.
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You lose a 1/3 of total space on a raid 5.

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 &nbsp;The 9 drives above were actually part of a raid group. The raid group would have shown me the correct values for the drives attached, but in my case we had two LUNs carved from this one raid group so the numbers were inconsistant.<br />
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Thank you.
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 The 9 drives above were actually part of a raid group. The raid group would have shown me the correct values for the drives attached, but in my case we had two LUNs carved from this one raid group so the numbers were inconsistant.

Thank you.

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 &nbsp; I would like to destroy an empty LUN and use it's drives, to create two new luns. The problem is my calculations for capacity do not match what Navisphere is telling me for the current LUN, so I am not willing to destroy this LUN until I know my calculations are correct and the drives will each be large enough after spliting.<br />
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Current LUN has 9 drives with these details. <br />
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Raw Capacity = 268.40<br />
User Capacity = 238.55<br />
<br />
It's currently a raid 5 LUN.... &nbsp; SO<br />
<br />
The described math I am using says multiply the smallest drive * number of drives - 1<br />
<br />
238.55 * 9 - 1 = 1908<br />
<br />
Navisphere shows all 9 drives to have a user Capacity of 1122.97
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   I would like to destroy an empty LUN and use it's drives, to create two new luns. The problem is my calculations for capacity do not match what Navisphere is telling me for the current LUN, so I am not willing to destroy this LUN until I know my calculations are correct and the drives will each be large enough after spliting.

Current LUN has 9 drives with these details. 

Raw Capacity = 268.40
User Capacity = 238.55

It's currently a raid 5 LUN....   SO

The described math I am using says multiply the smallest drive * number of drives - 1

238.55 * 9 - 1 = 1908

Navisphere shows all 9 drives to have a user Capacity of 1122.97

Raid 5 capacity question

Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media used to retain digital data. In addition to local storage devices like CD and DVD readers, hard drives and flash drives, solid state drives can hold enormous amounts of data in a very small device. Cloud services and other new forms of remote storage also add to the capacity of devices and their ability to access more data without building additional data storage into a device.

Storage

Storage devices include any device used for storing and retrieving digital information. Hard disk drives (HDDs) use one or more rigid ("hard") rapidly rotating disks (platters) coated with magnetic material. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order and not only sequentially. The primary competing technology for secondary storage is flash memory in the form of solid-state drives (SSDs), but HDDs remain the dominant medium for secondary storage due to advantages in price per bit and per-device recording capacity. CD-RW (Compact Disc-ReWritable) is a digital optical disc storage format that allows information to be stored outside the mechanical HDD.