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I have a 3.46 tb raid disk array, but in volumes it shows it only as 2.00TB

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What have I done wrong, and how can I fix it? Thanks Noam

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up vote 11 down vote accepted

You must use a GPT partition table for windows to use disks over 2TB. You've likely configured it as MBR.

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How do I do that? Do I need to reformat my machine, or where do I configure it now? – Noam Aug 22 '13 at 12:40
Your BIOS needs to support boot from GPT (EFI), if it does the server install will automatically detect it and use it. You'll have to fiddle with your BIOS settings and reinstall if you want to boot from that large volume. Alternatively you can use a smaller boot volume and use the 3+TB volume as a non-boot disk and just reformat it selecting GPT. – MDMarra Aug 22 '13 at 12:42

You're using MBR, which supports a max of a 2 TB partition. Either make a new partition for the remaining space, or start all over again with a GPT partition.

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Can you do a spanned volume to the boot disk? – MDMarra Aug 22 '13 at 12:42
I'm thinking so, but I'm too lazy to look it up. – mfinni Aug 22 '13 at 12:43
Meh. Looks like you're right. – mfinni Aug 22 '13 at 13:03

Did you format the disk to use GPT and not the MBR cause to use disk with more than 2To you have to use GPT as MBR is limited to 2To.

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I think the only reason for showing your disk array only as 2.00TB is that the remaining volume is reserved as a virtual memory or virtual space. For example some application need large space to run or to start. When you try to open these applications it requires some memory which it either take it from system or from other memory resources. And every memory unit has some space reserved for this purpose. Those invisible memory that are not shown on your disk are used by the applications to run. So, here comes the concept of virtual memory.

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This seriously demonstrates a total lack of understanding of how Windows works in general and how virtual memory on Windows works in particular. – RobM Aug 22 '13 at 18:54
Virtual Memory is not what you seem to think it is. You also seem to be conflating the idea of swap (paging) - using disk space as "extra memory" to hold inactive data - with the core issue here (see the other two answers). Swap space is not "invisible", and is always shown on the disk - either as a file (the way Windows typically does it) or a separate partition (the way Unix typically does it). – voretaq7 Aug 22 '13 at 19:15
You're describing memory address allocation limitations, not virtual memory. That said, it's still not correct. Windows Server 2012 is x64 only, which puts the theoretical limit of memory addresses out of the reach of modern hardware. Even if it was the problem, it doesn't apply to storage. What you're seeing is a well known limit of the legacy MBR partition table, which has a 2TB limit. This is well known and using the newer GPT partition table is the solution. Sorry, not trying to pile on to the downvotes, but I just wanted to let you know why you were wrong. – MDMarra Aug 22 '13 at 19:15
This answer is kind of awesome. Which is not to say, useful or truthful in any way. But still awesome. – mfinni Aug 22 '13 at 19:26
@mfinni the archaic definition of "inspiring fear" needs to be resurrected to the mainstream. – Dan Neely Aug 22 '13 at 20:06

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