If you cannot resize a VM disk on ESXi, please check the following points:
Your disk is SCSI or SATA on the appropriate SCSI or SATA controller
Your disk uses thin provisioning
Your VM does not have VMware snapshots
You didn’t modify the disk’s size and it’s position in the boot sequence at the same time
You didn’t try to reduce the size of the disk
Other important points to remember:
Expanding a disk can damage the data or operating system installed on the disk. You may need to apply additional operating system tools or processes before you can use an expanded disk.
In private cloud, before you deploy a VM, you cannot resize the system disk.
If you resize a system disk and then undeploy the VM or create an instance, when you deploy again the platform will copy the hard disk and/or its size from the template, which may change the size. You may need to perform more actions before you deploy the template, such as promoting the secondary instance template and entering the correct deployed size as the capacity.