diff --git a/pulsar/managers/base/__init__.py b/pulsar/managers/base/__init__.py
index 857e375edf789a0da5883332677b495bc33af744..6c448df40881a415df169e2d6b9f99084f407c93 100644
--- a/pulsar/managers/base/__init__.py
+++ b/pulsar/managers/base/__init__.py
@@ -3,6 +3,7 @@ Base Classes and Infrastructure Supporting Concret Manager Implementations.
 
 """
 from collections import deque
+import errno
 import logging
 import os
 from os.path import exists, isdir, join, basename
@@ -369,7 +370,11 @@ class DirectoryMaker(object):
         makedir_args = [path]
         if self.mode is not None:
             makedir_args.append(self.mode)
-        if recursive:
-            makedirs(*makedir_args)
-        else:
-            os.mkdir(*makedir_args)
+        try:
+            if recursive:
+                makedirs(*makedir_args)
+            else:
+                os.mkdir(*makedir_args)
+        except (OSError, IOError) as exc:
+            if exc.errno != errno.EEXIST:
+                raise
diff --git a/pulsar/managers/util/job_script/CLUSTER_SLOTS_STATEMENT.sh b/pulsar/managers/util/job_script/CLUSTER_SLOTS_STATEMENT.sh
index 0b35a4b9c35df9e58405a724558188eb17018451..3e59bbd0770d5cc087d6a78e3a6f8907b5478c0b 100644
--- a/pulsar/managers/util/job_script/CLUSTER_SLOTS_STATEMENT.sh
+++ b/pulsar/managers/util/job_script/CLUSTER_SLOTS_STATEMENT.sh
@@ -1,9 +1,18 @@
 export GALAXY_SLOTS_CONFIGURED="1"
-if [ -n "$SLURM_NTASKS" ]; then
-    # May want to multiply this by ${SLURM_CPUS_PER_TASK:-1}.
-    # SLURM_NTASKS is total tasks over all nodes so this is 
-    # shouldn't be used for multi-node requests.
-    GALAXY_SLOTS="$SLURM_NTASKS"
+if [ -n "$SLURM_CPUS_ON_NODE" ]; then
+    # This should be valid on SLURM except in the case that srun is used to
+    # submit additional job steps under an existing allocation, which we do not
+    # currently do.
+    GALAXY_SLOTS="$SLURM_CPUS_ON_NODE"
+elif [ -n "$SLURM_NTASKS" ] || [ -n "$SLURM_CPUS_PER_TASK" ]; then
+    # $SLURM_CPUS_ON_NODE should be set correctly on SLURM (even on old
+    # installations), but keep the $SLURM_NTASKS logic as a backup since this
+    # was the previous method under SLURM.
+    #
+    # Multiply these values since SLURM_NTASKS is total tasks over all nodes.
+    # GALAXY_SLOTS maps to CPUS on a single node and shouldn't be used for
+    # multi-node requests.
+    GALAXY_SLOTS=`expr "${SLURM_NTASKS:-1}" \* "${SLURM_CPUS_PER_TASK:-1}"`
 elif [ -n "$NSLOTS" ]; then
     GALAXY_SLOTS="$NSLOTS"
 elif [ -n "$PBS_NCPUS" ]; then