Thanks. I had the same problem. This solution worked beautifully. I'm trying it on a RHEL4 vmdk now. I'll let you know how it turns out.

this is just a 2nd disk?

this is another disk split into multiple files?

eitherway:
start - run - cmd and change directory to vmware workstation installation dir and then:

(reminder, perhaps take a copy of your vmdks before you start executing, just to be sure )
vmware-vdiskmanager.exe -r RHEL 4.2.vmdk -t 2 newSolidRHEL.vmdk

then you can winscp the newSolidRHEL.vmdk to your ESX and follow the vmkfs-tools story

vmware-vdiskmanager is a comand line utitlity which can be found on your windows device (the one where vmware server or gsx or workstation is installed)

ESX does not have this utility

esiebert7625, thanks for the great method!

Not sure when you're receiving this error message, but I had the same thing when using WinSCP with file transfer resumption enabled. WinSCP appends a ".part" suffix to the file while it is transferring in order to have a resumption point. Once the transfer is complete, it tries to rename the file, which is where I received the same error.

There are two solutions to this:

1) Start WinSCP, in the left window select Preferences, press the Preferences... button. In the left window, under Transfer, select Endurance. In the "Enable transfer resume/transfer to temporary filename for" area, select the Disable radio button.

2) If you have already transferred the file and do not want to push it again, tell WinSCP to skip the renaming of the file when you receive this error. Then SSH into the box or browse the datastore with VIC and rename the file with "mv /vmfs/volumes/san001/temp/virtdisk.vmdk.part /vmfs/volumes/san001/temp/virtdisk.vmdk". I tested the .part file against my source with md5 checksum and they are the same file.

Hope this helps someone...