The virtual machine’s hard disk is stored as one or more files on the host computer’s physical disk. These file(s) start small and become larger as you add applications, files, and data to your virtual machine.
At the time of creating the virtual machine you might have chosen to Split the virtual disk into multiple files maybe because you keep on moving/copying the virtual machine from one computer to another or there was some space constraint or maybe you might be on a file system which does not support creating larger files.
Though a split-virtual disk has some advantages, but it may reduce performance with very large disks.
If you need to merge these split-files into a single VMDK , there is a tool vmware-vdiskmanager.exe to do the job for you.
You can download the tool from here and extract it to the location of your choice. Preferred location would be the location where virtual machine is stored.
Open the command prompt and execute the following command
vmware-vdiskmanager.exe –r path\to\the\headfile.vmdk –t 0 path\to\new\merge\mergedfile.vmdk
The source file(headfile.vmdk) is the selected file in the image below.
Don’t forget to defragment your new created vmdk.