I've seen cases where a newly extended VMFS datastore fluctuates between the old size and the new size. Virtual Machines running on th newly extended datastore prevents the correct size of the datastore from displaying.
I found the solution to the problem in KB Article 1002558
Products: VMware ESX and ESXi
The solution is:
- Shut down or VMotion virtual machines running on the extended datastore to the ESX host that created the extent.
- On all other ESX hosts other than the one that created the datastore, run vmkfstools -V to re-read the volume information.
- Power on or VMotion the Virtual Machines back to the original ESX hosts.
This is not only on VI3 hosts but on:
VMware ESX 2.0.x
VMware ESX 2.1.x
VMware ESX 2.5.x
VMware ESX 3.0.x
VMware ESX 3.5.x
VMware ESXi 3.5.x Embedded
VMware ESXi 3.5.x Installable