Testing disk I/O speed on a single EBS volume, vs a RAID0 volume made of 2 EBS volumes.

gistfile1.py

import os
import time

def writeBytes(size,fileName):
  start = time.time()
  cmd = "dd if=/dev/zero of=" + fileName + " bs=" + size + " count=1 status=noxfer > /dev/null"
  print cmd
  os.system(cmd)
  return time.time() - start

SINGLE="/home/ubuntu/data/singleEBS"
RAID0="/home/ubuntu/data/raid0EBS"

#test with smaller sizes                                                                                                                                                                                                                                                      
FILE_SIZES=['4k','8k','16k','32k','64k','128k','256k','512k']
#test with bigger sizes                                                                                                                                                                                                                                                       
FILE_SIZES=['128M']

def writeNFiles(PATH,N):
  total_time = 0
  for size in FILE_SIZES:
    for i in xrange(0,N):
      total_time += writeBytes(size,PATH+"/"+size+"-"+str(i))

  return total_time

total_time=0
REPETITIONS=1
N_FILES=9
for i in xrange(0,REPETITIONS):
  total_time += writeNFiles(SINGLE,N_FILES)
outputA = "("+str(total_time)+") Total time for " + SINGLE

total_time=0
for i in xrange(0,REPETITIONS):
  total_time += writeNFiles(RAID0,N_FILES)
outputB = "("+str(total_time)+") Total time for " + RAID0

print "\n\n"
print outputA
print outputB
print "\n"

#
# Results. Single EBS is faster when writing a lot of small files.
# RAID0 is faster when writing bigger files (from tens of MBs to over 128MB on this last test)
# AWS EBS EC2 tests