MatLab + Windows + UNC + HTCondor (generic scheduler)

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Mark
Mark on 1 Apr 2013
Hello all and thanks for reading / giving some input:
We have set up a simple lab with one node acting both as master and execute on Win 7 (no domain). Same unit has MatLab.
There is a NAS device on the network accessed with UNC paths.
We've set up Condor to launch MatLab with user impersonation and the condor_submit description file uses run_as_owner = true.
When invoking Matlab through Condor and watching Task Manager we can see MatLab launching as the submitting user.
Here is the anomaly:
When launching MatLab from the standard desktop by icon, within MatLab the Path entries to the UNC share are there and no warning is posted on startup.
When launching MatLab from a CMD windows with MatLab -r mFile, MatLab launches, executes mFile, and again there are no warnings in respect to Path entries.
When we launch through Condor, we are presented with a warning about all the UNC Path entries:
Warning: Directory access failure: \\Diskstation\Matlab Warning: Directory access failure: \\Diskstation\Matlab\Data
.... [edited for brevity]
This information is being trapped launching MatLab with the -logfile switch within Condor.
No errors are reported within Condor and the instantiated MatLab (under the user's account) simply hangs until we kill it through Task Manager.
There are no access denied logs on the UNC device, and the shares are globally open - read / write / browse.
Any thoughts on how to hunt this problem down is appreciated.
This question has also been submitted to the HTCondor community in hopes of some shared knowledge found.
Many thanks.

Answers (1)

Jason Ross
Jason Ross on 2 Apr 2013
I'm suspecting that the account doing the launching is the LocalSystem account. This account (by design) has no access to the network at all. Although you do indicate that user switching should happen, it sounds like it happens too late.
To do a quick and dirty test of this, use the PSTools (<http://technet.microsoft.com/en-us/sysinternals/bb896649.aspx>) to launch a command shell as the LocalSystem account:
psexec -i -s cmd.exe
In this command shell, map the UNC with the user credentials
net use \\unc\path /user:USERDOMAIN\username
it will then allow you to authenticate (you can also do this on the command line, but that puts your password in plain text)
Then run your command again and see if it works.
  3 Comments
Mark
Mark on 10 Apr 2013
Hi Jason - I wanted to take a quick moment and thank you for your additional response and clarification. I'll have to revert on specific answers nd continue my discovery.
The shame is there is no ability to pass a RunAs w/ credentials from within a Condor job submission (that I am aware of). In an AD domain this issue falls away but when dealing with siloed workstations in a workgroup the challange appears pretty large.
Mark

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