If you intend to install/run Windows on a non-local filesystem (such as an
NFS mounted home directory), you will need to set 2 environment variables to
point to a writeable directory mounted on a local disk.  This directory should
have plenty of free space as both a Windows "memory image" and the Windows
swapfile will be created there.

The 2 variables are:

MERGE_MEMIMG_DIR
(points to the directory where to store the memory image)

MERGE_WINDOWS_SWAPDIR
(points to the directory where to store the Windows swapfile)

You will need to set these variables before running 'win' or 'dos'; here are
examples for both csh and sh shell variants:

csh:
	setenv MERGE_MEMIMG_DIR /tmp
	setenv MERGE_WINDOWS_SWAPDIR /tmp

sh:
	MERGE_MEMIMG_DIR=/tmp; export MERGE_MEMIMG_DIR
	MERGE_WINDOWS_SWAPDIR=/tmp; export MERGE_WINDOWS_SWAPDIR

Replace /tmp with whatever writeable local disk directory you prefer.

If you do not have a local disk or do not have much free space on a local disk,
you can override this requirement by setting the environment variable
MERGE_DISABLE_FILESYSTEM_MMAP_CHECK to "on"; note that it is strongly
recommended that if at all possible the local disk method (mentioned above)
is used, since performance will be far greater.

To make these settings global, input the values into /etc/default/merge

