The redo log file is placed in the same directory as the disk file by default. However, the location of the redo log file can be changed in the Configuration Editor under Miscellaneous. Nonpersistent disks are convenient for people who always want to start with a virtual machine in the same state. Example uses include providing known environments for software test and technical support users as well as doing demonstrations of software. Any disk type can be used in nonpersistent mode.
Workstation only reads the disk.
Any writes to the disk during the session are actually written to a redo log file that is deleted at the end of the session when you power off or reset the virtual machine. When the virtual machine is running, any blocks that have been modified and written to the redo log file are read from the redo log file instead of the disk. When the virtual machine is powered off, the redo log file is discarded. The guest operating system is entirely unaware that the disk is nonpersistent. Some disk operations may even be faster on a Workstation nonpersistent disk than on an actual disk.