VMWare vmkfstools not Cloning the full size of the VMDK over. (16gb out of 50gb)

Wayne Barron
Wayne Barron used Ask the Experts™
Would someone have an explanation for this?

Both times I have run this script.

vmkfstools -i "/vmfs/volumes/Date-2016/00 - DNS Server/00 - DNS Server.vmdk" -d thin "/vmfs/volumes/DES Lessons/00-DNS-Serve
r/00 - DNS Server.vmdk"

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It gets to around 45%, and then jumps to 100%

Destination disk format: VMFS thin-provisioned
Cloning disk '/vmfs/volumes/Date-2016/00 - DNS Server/00 - DNS Server.vmdk'...
Clone: 100% done.

However, the actual size is 50GB
But the file transferred is only 16GB

00 - DNS Server.vmdk
16.53 GB
Sunday, May 20, 2018, 12:48:59 -0400

This is the actual size

00 - DNS Server.vmdk
50 GB
Saturday, April 28, 2018, 08:23:53 -0400

I have 7 VMs that need to be moved to a new drive, and this is causing some major slowing down issues.
Any ideas?

Also, if using the vmkfstools GUI is a better route to go, that would complete this without this issue.
Then please, tell me how to use the GUI, as I cannot find any information on using it.

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Author, Web Developer
Top Expert 2009
I just read that the clone disk is a lot smaller than the original.
OK, I can deal with that.
If anyone would like to confirm this, please do so.
Wayne BarronAuthor, Web Developer
Top Expert 2009


Yep, makes it into a small file.
I can deal with this.
Makes my job a LOT faster.
Just wish I would have known about this earlier, as I thought it had messed up, so I deleted the file and re-cloned it again.
We live, we learn.

All good now.
Luciano PatrãoICT Senior Infraestructure  Engineer  

Clone will only copy data, not empty blocks. So if you Guest OS is only 16Gb of data, you will have only 16Gb of that. Particularly when you are using thin option.
Wayne BarronAuthor, Web Developer
Top Expert 2009


Thanks, Luciano.
During my research, I found this out.

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