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David GerlerFlag for United States of America

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RAID 50 logical disk split when installing MS Hyper-V free version

I am working on creating a Software SAN solution and before paying for the licenses neccessary I am using free versions to test.

I created a RAID 50 logical disk out of (6) 2 TB drives which gave me a drive with about 7.2 TB space. When I was installing Hyper-V at the disk prep screen, I created a partition for Hyper-V of about 89414 MB. When the screen refreshed I had the new partition and two sections of unpartitioned space. One was about 5400 GB and the other was about 1900 GB. I was able to partition the 1900GB portion, but when I attempt to partition the 5400GB portion it can't create the partition. Now even when I remove all partition, it show two sections of unallocated space (2048 and 5402). Is 2 TB the largest partioton Windows can deal with?

I also tried with Windows Server 2008 Standard and have the same problem.
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Andrew Hancock (VMware vExpert PRO / EE Fellow/British Beekeeper)
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The BOOT Partition cannot be more than 2TB.
It is the largest that MBR volumes can be. they have a max of 2 tb.  To go larger, you need to use GPT what ever the partition is used for.

Starting with Windows Server 2003 Service Pack 1, all versions of Windows Server can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on Itanium-based systems.

Actually, the logical disk can't be larger than 2 TB unless it is using GPT partitioning instead of MBR partitioning type. The trick is that regular BIOS requires MBR disks for booting. Check with your server manufacturer to see if they support UEFI booting, will is next generation replacement for the BIOS and should support GPT disks.

If that doesn't work, use the RAID controller to create a smaller RAID set of maybe 100 GB for the OS, and then a larger RAID set of the remaining space for the VMs. The first RAID set can then be MBR and you can install the OS as normal, and the second drive can be GPT to support the very large partition.
if it was me I would carve up the RAID 50, into two logical drives, virtual disks, whatever your RAID controller refers to them as

Create one small one for the OS Hyper-V 40 to 300GB
Create a second for the VMs.
@neilsr, it appears that 64 bit versions of Vista/2008 and later support booting to GPT disks on UEFI systems. That said, I have never set a server to UEFI boot. Considering the fact that there can be rebuild issues with RAID controllers that have multiple RAID sets where 1 or more of the logical RAID disks doesn't rebuild after a failed drive.

http://msdn.microsoft.com/en-us/windows/hardware/gg463525
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Wow! Great response guys! My physical disks are all 2TB drives.  

So I am hearing create a RAID 1 set for the OS and another RAID5 set of the other (4) 2 TB drives? How do I use GPT?
Not, exactly split the array if you can by carving it to create two logical drives, this way you will benefit because logical drives will be stripped across all 6 disks if possible.

To use GPT, just create the volume required at the correct size.
I would not use 2 TB drives in RAID 1 for the OS. That is a waste of 2 TB drives, and it leaves you with only 4 drives for the VMs, which can leave you with a lot of space, but not a lot of performance. If your server fits 8 drives, take 2 small drives in RAID 1 for the OS and then use the 6 drives in a RAID 10 (better) or RAID 50 (not as good, but still better than RAID 5). I assume that these drives are Enterprise SATA or NLSAS. Either way, they will be 7.2K drives and they can't provide a lot of IOPS, which limits the number of VMs you can concurrently support. 10K SAS drives provide significantly more IOPS, and therefore many more VMs.

I would try to install on a GPT disk before creating two RAID sets because of known issues with RAID rebuilds when there are multiple RAID sets.

Windows 2008 R2 Install on UEFI and GPT
http://www.mytechcorner.net/2011/07/windows-2008-r2-install-on-uefi-and-gpt.html
The server only have 6 drives. They are SAS drives and yes 7.2k.

A little background.. This is a SAN I am building to accept replication of 9 VM's that are not currently backed up at the host level. So when one goes down a new machine has to be created and software installed before restoring the data. This is the first "economical" step for a small company towards our ideal DR plan. I understand that performance will not be ideal, but we'll make do with what we can afford right now.

Keeping that in mind, what's the best method to use these 2TB drives to give me the best performance / space to handle 9 VM's? I do have a couple 73GB drives I could use for the OS, but then I would still be limited to 4 of the big drives.
does your RAID controller not have the function to carve up the Array into smaller chunks?
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kevinhsieh
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The VMware host is another box entirely. This box is intended to be a software SAN accessed via iSCSI.
 
The server is a Dell 2950 with Perc 5/i RAID Controller.

Okay if this is a software SAN, drop HyperV, install Windows Server 2008, 40GB volume, split RAID array into two logical volumes, and either user ISCSI Target or Starwind Software.

I do not know why you need to install a hypervisor, this servers needs fast RAID 10 storage.
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I created 1 VD RAID 10 with 6 2TB disks. I got 1 VD about 5.4 GB. That is still enough space for what I need. So now when I install windows and create a partition for the OS I get the the 100MB, 40GB primaries and 1940Gb unallocated and 3700GB unallocated.

So I figured I need to convert it to GPT. I tried with DISKPART but it won't let me because it contains the boot partition.
ok. I was able to find diskpart by aborting the windows install and "repairing". I cleaned the disk and converted it to a GPT disk. I created the 100MB primary, a 40GB primary and now I'm wondering should I make the rest a primary partition?
well, Windows won't install on the 40GB partition because it's GPT.

I looked in the BIOS and which is 2.7.0, but I did not find anything about GPT or UEFI. Does that mean I'm stuck with using RAID 1 for two drives one set of drives and making a separate RAID10 Set with 4 drives?

Will the Starwinds software allow me to use the large portion of the OS RAID1 set along with the RAID10 set?
Did you go over this link for installing on GPT disk?

Windows 2008 R2 Install on UEFI and GPT
http://www.mytechcorner.net/2011/07/windows-2008-r2-install-on-uefi-and-gpt.html
I could not find anywhere to set the boot to UEFI in the BIOS. I finally found how to create the smaller slices of the RAID1 so the First two disks are RAID1 with 40GB Virtual disk another virtual disk with the rest.
How should I format the GPT drives? NTFS?
Format all drives for servers NTFS. If they are holding VMs, I use 64k clusters.
Thanks Kevin
Hanccocka, is Andysworld your website? If so, how do I get the sound to work? I get sound from website all the time, but it doesn't work for those videos.
andysworld is my blog, there is no sound track on the videos.