I have read through the previous threads about some of the issues related to UNC paths, Python, etc. This turning out to be a huge problem for us. We are trying to enable an open source Python project (IPython: ipython.scipy.org) to work with the scheduler. In particular we have a command line program that we want to use to submit parallel Python jobs for users (it is actually more complicated than that, but from the scheduler perspective, that is it). I want to make sure I understand the issues related to paths...
Are the following correct descriptions?
* It looks like you have to use a UNC path for the working directory, rather than a mapped drive.
* But, cmd.exe doesn't accept this so it defaults the working dir to C:\Windows.
* But, the environment variables get set correctly (%CCP_WORKDIR%)
* But muchof Python cannot handle UNC directories. I am still trying to figure out what parts can and can't handle UNC paths, but this looks like this might be a huge issue for us.
* It looks like the %PATH% environment variable is completely ignored when finding executables run by tasks. This, in combination with the ban on mapped drives, means that if an executable is on a shared drive, you have to give its UNC path at the command line: \\server\share\program.exe
* Are drives simply never mapped on the compute nodes? From my tests, it looks like sometimes they are. For example, sometimes my python script can do os.chdir(r'z:\\documents') on a compute node. Sometimes not. Am I just asking for trouble here?
* We need a robust UNC based method of finding a users home directory. Currently we use %homedrive%%homepath%, but that gives us the mapped drive version. It looks like %HOMESHARE% might have the information in UNC form, but are we always guaranteed that will give the UNC path to the home directory? What if the home directory for a user is local (not shared) - what is %HOMESHARE% in that case?
It seems like the things I was describing above are basically the case. It seems that the golden rule for paths with the scheduler is to use UNC paths everywhere.
I have managed to get Python to handle these at the level I need them to, so even though all this is quite awkward, I can move forward.
It seems like the things I was describing above are basically the case. It seems that the golden rule for paths with the scheduler is to use UNC paths everywhere.
I have managed to get Python to handle these at the level I need them to, so even though all this is quite awkward, I can move forward.
Brian, We always recommend using UNC Paths. Drive mapping is not a per-user setting. They may persist between some sessions and not others (I'm not exactly sure how it works). If you can find a way to enforce them across sessions (it may be possible with Group Policy) go for it, but we recommend UNC Paths as the most reliable way to access shares.
