Hi all, I am trying to make a simple density projection of my data using yt on kraken. I have done this successfully many times before both on kraken and other machines, but lately I have been getting errors on kraken. I tried to run it interactively and it worked, but when I submit it as a job, I get this error: P000 yt : [INFO ] 2012-02-24 03:40:43,722 Created plot collection with default plot-center = [0.50027465 8203125, 0.500335693359375, 0.499969482421875] Traceback (most recent call last): File "/var/spool/alps/8952326/try1.py", line 8, in <module> profile("Feb2012/cluster_64/",imax=20) File "/lustre/scratch/yuan/enzo_yt/cluster256_nog/yuan.py", line 23, in profile File "/lustre/scratch/yuan/enzo_yt/cluster256_nog/yuan.py", line 23, in profile pc.add_projection("Density", 0) File "/lustre/scratch/proj/sw/yt/dev/lib/python2.7/site-packages/yt-2.4dev-py2.7-linux-x86_64.egg/yt/visua lization/plot_collection.py", line 758, in add_projection P000 yt : [INFO ] 2012-02-24 03:40:43,919 Starting 'Projecting level 0 / 8 ' **field_parameters) **field_parameters) File "/lustre/scratch/proj/sw/yt/dev/lib/python2.7/site-packages/yt-2.4dev-py2.7-linux-x86_64. egg/yt/data_objects/data_containers.py", line 1648, in __init__ File "/lustre/scratch/proj/sw/yt/dev/lib/python2.7/site-packages/yt-2.4dev-py2.7-linux-x86_64.egg/yt/data_ objects/data_containers.py", line 309, in _refresh_data ....... File "/lustre/scratch/proj/sw/yt/dev/lib/python2.7/site-packages/yt-2.4dev-py2.7-linux-x86_64.egg/yt/funcs .py", line 104, in get_memory_usage return float(os.popen('ps -o rss= -p %d' % pid).read()) / 1024 ValueError: could not convert string to float: PID Uid VmSize Stat Command 1 root 584 S init 2 root SW [migration/0] 3 root SWN [ksoftirqd/0] 4 root SW [migration/1] 5 roo It seems that something went wrong at "get_memory_usage", but I had never had this error before and an interactive job does not get this error either. Sorry the error message is quite messy... Yuan