Check whether the file system of the disk storing the vmdk file is FAT32. Generally speaking, the FAT32 file system does not allow a single file to be larger than 4G, so when your disk file is larger than 4G. Other vmdk files will be created, and many smaller files will be created, because they are not written once, but allocated dynamically. The way to avoid this problem is to store vmdk files in the partition of NTFS file system.