diff --git a/wally/suits/io/ceph.cfg b/wally/suits/io/ceph.cfg
index a10adfb..f38b37c 100644
--- a/wally/suits/io/ceph.cfg
+++ b/wally/suits/io/ceph.cfg
@@ -15,7 +15,7 @@
 NUMJOBS={% 1, 5, 10, 15, 40 %}
 NUMJOBS_SHORT={% 1, 2, 3, 10 %}
 
-size=30G
+size=100G
 ramp_time=15
 runtime=60
 
diff --git a/wally/suits/io/vm_count_ec2.cfg b/wally/suits/io/vm_count_ec2.cfg
index c132039..c6fc56c 100644
--- a/wally/suits/io/vm_count_ec2.cfg
+++ b/wally/suits/io/vm_count_ec2.cfg
@@ -1,30 +1,37 @@
 [defaults]
-NUM_ROUNDS=7
-ramp_time=5
 buffered=0
-wait_for_previous
+wait_for_previous=1
 filename={FILENAME}
 iodepth=1
 size=10G
-time_based
+
+# this is critical for correct results in multy-node run
+randrepeat=0
+
+time_based=1
+ramp_time=5
 runtime=30
-group_reporting
-rate={BW_LIMIT}
-rate_iops={IOPS_LIMIT}
-NUMJOBS={% 1, 2, 5, 10, 15, 20, 25, 30, 35, 40 %}
+
+group_reporting=1
+BW_LIMIT=60m
+IOPS_LIMIT=100
+
+NUMJOBS=1
+NUM_ROUNDS=7
 
 # ---------------------------------------------------------------------
 # check different thread count. (latency, bw) = func(th_count)
 # ---------------------------------------------------------------------
 [vm_count_{TEST_SUMM} * {NUM_ROUNDS}]
-blocksize={% 4k, 1m %}
+blocksize=16m
 rw={% randwrite, randread %}
 direct=1
 numjobs={NUMJOBS}
+rate={BW_LIMIT}
 
 [vm_count_{TEST_SUMM} * {NUM_ROUNDS}]
-blocksize={% 4k, 1m %}
-rw=randwrite
-direct=0
-sync=1
+blocksize=4k
+rw={% randwrite,randread %}
+direct=1
 numjobs={NUMJOBS}
+rate_iops={IOPS_LIMIT}