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I am trying to set up software raid on a win2008 R2 server core. I have the disks configured as dynamic. In the server manager gui, i can see the disks, but when i right click, the option to set up "new mirrored volume" is not listed. I tried it with the command line using diskpart, and it gives the error "Virtual Disk Service Error: The size of the extent is less than the minimum." The drive are a new pair of 1Tb disks.

Is this not supported in server core, or am i missing something else?

Thank you

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Are you right-clicking on an existing partition on a dynamic disk and adding a mirror, or trying to create a mirror on two unformatted disks? – Mark Henderson Aug 17 '09 at 5:06
I am right clicking on existing partitions on dynamic disks. – shimonyk Aug 17 '09 at 12:16

So is the size of the extent big enough? IE is the free unpartitioned space available big enough to house the partition you right-clicked? Some 1TB disks have different actual size...

Also, I'd normally just init the disks as basic disks, create a partition on one and then "add disk" to that one to create the mirror which would then do the conversion logic for me, instead of manually converting to dynamic disks first. Something akin to (not tested for syntax perfect-ness and only applicable if this is a data volume, not the boot volume ;):

clean all
create volume simple disk=1
add disk=2
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Oh, I gave up on this months ago. I reimaged the box to a full install and everything just worked. It seems to me so far that server core adds a lot of administrative overhead without adding much benefit. Thanks for asking though. – shimonyk Jan 13 '10 at 16:04
I ran into the same problem on 2003 server when there was no unpartitioned space. After decreasing size of one of the existing partitions, mirroring in disk management started to work. – Dmitry Trukhanov Apr 7 '10 at 7:47

Did you setup the disks as MBR or GPT? To get over 2 TB of space you'll need to use GPT.

What commands are you using in diskpart?

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The total space is 2Tb. With the mirror it will be only 1Tb. How do I check if it is mbr or gpt? The diskpart command is CREATE VOLUME MIRROR DISK=1,2 – shimonyk Aug 17 '09 at 12:10

If you are using 32bit os then it should default to mbr. Not so much default, but use mbr as standard. 64bit will use gpt as standard. there is a command line to change it back and forth, but as for 32 and 64bit, the os will determine which will be used.....susposedly

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up vote 0 down vote accepted

FYI, I gave up on this after about a month and never found a solution. I reimaged the box to a full install (non-server core) and everything just worked. It seems to me so far that server core adds a lot of administrative overhead without adding much benefit.

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