Some of the options you have with respect to managing disk space include the following:

• setting the total size of each virtual disk file
• adding subsequent virtual disk files in order to increase total disk space

You cannot change disk size after you have installed a disk.

The value that you specified for Capacity determines the maximum size of the disk. The disk automatically grows in size, as needed, up to this limit.

The treatment and use of disk space are different for the disk modes, particularly with respect to the setting for Capacity:

• A persistent disk (that is, the underlying virtual disk file) can grow up to Capacity, and has no associated redo log that requires disk space.
• A nonpersistent disk (again, actually the virtual disk file) will never increase or decrease in size as long as it is opened in nonpersistent mode. However, the redo log file that records file activity will grow as large as required, as it is not limited by the setting for Capacity. The redo log is discarded at the termination of each VM session, so these files do not accumulate. Nevertheless, a long or complex session might result in a large file, which can potentially use up all available disk space.
• An undoable disk is treated similarly to a nonpersistent disk. However, because you can choose to keep (accumulate) changes for any number of VM sessions, the redo log has the potential to grow quite large. So, as with nonpersistent disks, you should keep this in mind, and monitor disk space if you use undoable mode.
• If you use any undoable or nonpersistent disks, you can move the location of the redo logs to a file system where you know there will be adequate space. Use the VM configuration editor to make this change. If you do use a non-default location, it should be on a local drive, not a remotely mounted file system, for optimal performance.

Once you have defined a disk, you cannot directly modify its size. You cannot enlarge or reduce the size of a currently defined IDE drive.

However, you can increase total disk space available to a VM by simply adding another IDE drive.