[Bluej-discuss] Unable to create virtual machine
mik at mip.sdu.dk
Thu Oct 21 01:26:02 EST 2004
On Oct 19, 2004, at 18:46, Todd O'Bryan wrote:
> My students just started using BlueJ today. Well, they tried to. It
> runs fine for me as an Administrator, but they keep getting "Unable to
> create virtual machine" messages that kill the whole program. Since I
> don't think the TCP/IP settings are different for the two types of
> accounts, it seems like the FAQ version of the problem is not the
> problem. (Though I guess it could be. Can somebody tell me how to
> check? We're not using a firewall.)
This one is new to me. We have seen other kinds of problems related to
not being Administrator on frozen machines, but not the 'create VM'
problem. So I cannot offer very good advice.
One shimmer of hope is this (if you can wait a few days): we are close
to releasing the next maintenance version (2.0.2) - probably in two
days or so. (This includes the fix for printing stack traces that one
esteemed reader of this list so eloquently requested ;-)
In this next release we have also added an alternative protocol for
BlueJ's two VM to talk to each other. This protocol does not use
TCP/IP, and we have done this specifically to avoid these kind of
problems. (The "Cannot create virtual machine" problem in conjunction
with various network/firewall configurations is the most common problem
reported to our technical support.)
If it is indeed the TCP/IP access that is causing your problem, then
this should provide a solution.
> The machines are fairly locked down so that students can't run
> programs except in specified directories. Which ones need to be open
> for BlueJ to work?
BlueJ needs read access to its own installation directory and
subdirectories, and the JDK installation directory.
On Windows, it needs write access to <user_home> (which I think is
'Documents and Setting/<username>' or something similar) where it will
create a directory named 'bluej' to store personal preferences.
It will also try to read the registry to find out which Java version to
use. If run for the very first time, it will attempt to write the
selected Java version to the user space in the registry.
Michael Kölling Mærsk Institute
http://www.mip.sdu.dk/~mik University of Southern Denmark
More information about the bluej-discuss