Fix only doing one disk when list of disks is provided

fio/fio_run

@@ -96,9 +96,9 @@ else
 	fi
 fi
 
+os_info=`uname -a`
 ubuntu=0
-uname -a | grep -q -E 'Ubuntu|tegra'
-if [[ $? -eq 0 ]]; then
+if [[ $os_info == *"Ubuntu"* ]]; then
 	ubuntu=1
 fi
 
@@ -109,7 +109,7 @@ ioengine="libaio"
 block_size=""
 test_type="read,write"
 ct_disk_size="undef"
-jobs_max="1"
+jobs_max=""
 jobs_min="1"
 tested=0
 run_time=120
@@ -505,9 +505,8 @@ obtain_disks()
 		max_disks=`echo $results | cut -d: -f 2`
 		disks=`echo $results | cut -d: -f 1`
 	else
-		disks=`echo $disks_passed | cut -d',' -f 1`
-		max_disks=`echo $disks | tr -d -c ' '  | awk '{ print length; }'`
-		let "max_disks=${max_disks}+1"
+		disks=`echo $disks_passed | sed "s/,/ /g"`
+		max_disks=`echo $disks | wc -w`
 	fi
 }