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For a task that is REALLY easy it took a more googling than I had anticipated to come up with the solution.  Once your volume has been delivered to the server it is important to initialize the disk but not to create any partitions.

1. Open Windows Disk management.
2. Click Action -> Rescan disks to make your new disk appear, if greater than 2tb it will appear as 2 partitions on 1 disk
3. Right click on the disk and initialize the disk
4. Open a windows command prompt
5. type “diskpart”
6. type “list disk”
7. select the new disk that’s over 2tb
8. convert gpt
9. Now from windows Disk Management you should see a single disk greater than 2tb

Information on the diskpart utility:   http://support.microsoft.com/default.aspx/kb/300415

The most important prereqs include Windows 2k3 is up to at least sp1 and that no partitions exist on the disk.

The purpose of this shootout was to analyze already backed up images of VM guests sitting idle on disk. We like to keep 7 days online, so I was curious as to how the two compared in our environment.

Compressed vs Deduplicated

COMPRESSED: (backed up via vRanger Pro over VCB, size on win NTFS volume)
citrix_server = 4.29gb
win_sql_server_64bit = 9.76gb
citrix_server2 = 6.14gb
win2k3_member = 4.97gb

compressed vm total = 25.16gb

UNCOMPRESSED:

citrix_server = 10gb
win_sql_server_64bit = 20gb
citrix_server2 = 10gb
win2k3_member = 35gb

uncompressed total = 75gb

DEDUPED VS COMPRESSED:

deduped     = 54.29% savings (NetApp cmd output below)
compressed     = 66.45% savings

Here’s the actual output from the NetApp find_space exe:
A-SIS Deduplication Space Savings estimate.

Name of Fingerprint File:          d:\esx_deduped.txt
Total Number of Directories:       5
Total Number of Files:             58
Total Number of 4K Blocks:         19662390
Total Number of Duplicate Blocks:  10673928
Percentage of Duplicate Data:      54.29
Scan Start Time:                   Wed, Jul 30 2008 3:40:16 PM
Scan End Time:                     Wed, Jul 30 2008 4:22:25 PM

I’ll be honest, I was expecting deduplication to blow compression out of the water even with only 4 vm’s. I’ll go out on a limb and venture that deduplication would provide more results as you toss more vm’s into the picture.

I’ve been doing a little testing with NetApp Deduplication lately but only in a limited test environment.  I know one thing for certain, deduplication and compression do not mix at all!  When you start to look at this technology make sure you’re dealing with uncompressed data.  This posting is more or less a bookmark for:

“Scott’s Quick Guide to Setting up Netapp Deduplication”

NetApp does provide a useful windows exe called “find_space” which you can run in report mode against any windows data volume.