VMWare ESXi 5 unable to create snapshot - maximum file size

I have a couple VMWare ESXi 5 servers, and on both of them I am unable to take a snapshot of one of my virtual machines (have tried moving the vm from one to the other). I am able to snap shot other machines.

I see an error within a few seconds in the vSphere Client: Create virtual machine snapshot
mymachine
File mymachine/mymachine.vmx is larger than
the maximum size supported by datastore '[2TB_1]

The data store consists of 1 2tb sata drive and has plenty of space (1.7TB free). The vm in question, vmdk file is just over 8gigs. All other files in it's directory as less than 1mb.

The datastore is VMFS 5.54, maxium file size 2.00TB, Block site 1MB (was originally setup this way, not converted from old version).

All the files in the vm folder look like the proper name "mymachine.xxx" (vmx/vmf/vmsd/nvram/vmdk).

Machine is powered off (was logically shut down). The guest is Windows Server 2008r2.

When I tell it to take a snapshot, it looks like it modifies the vmsd file based on it's modified date/time, but that's it.

Any ideas?

I have tried adding some parameters for workingDir and snapShotRedoNotWithParent per these pages and no difference: one two three

Also found a page mentioning that either the block size is not 1mb or the vmx is in a different directory than the vmdk - neither is true in this case.

Also, I even tried cloning the machine (to make sure all the files are named properly/the same and in the same directory), which worked fine, but the new clone will not snapshot, same error.

Here is what my datastore configuration looks like:

This is where the vmx / vmdk file is stored:
2TB_1
Normal
Local ATA Disk (t10.ATA_____ST2000DL0032D9VT166__________________________________5YD2HR2E):1
Non-SSD
1.82 TB
1.55 TB
VMFS5
4/22/2012 10:08:05 AM
Enabled

Disabled
Not supported
VMFS 5.54 Maximum File Size 2.00 TB, Block Size 1MB

this is the boot drive for vmware:
datastore1 (1)
Normal
Local ATA Disk (t10.ATA_____Patriot_Pyro____________________________PT1131A00007123_____):3
SSD
51.00 GB

50.05 GB
VMFS5
4/22/2012 10:08:05 AM
Enabled
Disabled
Unknown
VMFS 5.54 Maximum File Size 2.00 TB, Block Size 1MB

here is a pic of the vm's directory (after a fresh clone):

Answer

I came across the solution by chance - I right clicked on the vm and chose snapshot -> consolidate (even though there are currently no snap shots in the snap shot manager) and now it's fine. Now I can create a snap shot, delete, create a new one, etc. So consolidate fixed it.

UPDATE:

later, my snapshots were failing again, so I did a lot more research and finally, I believe I have the answer. It's because my VMDK (virtual disk) size is set to 2TB! Reading through this post, I thought maybe it's because my vmdk is defined as 2TB, and my physical datastore disk is only 1.9TB. I would think it should not be an issue, since it's thin provisioned, but in fact, after using vmware tools to copy the machine and make the disk smaller (1.5TB) (other methods here for shrinking the disk here) everything seems to work working fine now!