"Insufficient disk space on datastore" error during "Create Virtual Machine"

During a conversion to a VMware Infrastructure/ESX 3 Server, the "Create Virtual Machine" step goes into a recoverable error with the following message:

The CreateVM_Task submitted to the VMware ESX server failed:  Insufficient disk space on datastore

The CreateVM_Task submitted to the VMware ESX server failed: A general system error occurred: The file is too big for the filesystem

The above error will occur if any of the following is true:

1. There is not enough disk space on the target host to create the .vmdk file
2. The block size of the VMFS partition needs to be increased to support the desired size of the .vmdk

The default configuration of the VMFS File System on a VMware Infrastructre/ESX 3 Server uses a block-size of 1 MB - which limits any individual .vmdk file to a maximum size of 256 GB. 

In order to be able to create a virtual disk with a size greater than 256 GB, the VMFS File System must be configured to use a larger block-size such as 2 or 4 MB. 

Please note that in order to apply the larger block size change, users will need to do one of the following:

1. Create a new VMFS partition with the larger block size
2. Re-format the existing VMFS partition to apply the large block size change

If you have any questions regarding this article, please contact PlateSpin Support at:  support.powerconvert@platespin.com