Intel Modular Server SSD and SAS disk performance

Buffered and cached disk reads with hdparm.
Seek time performance with python seeker.
Additional performance with fio. fio tutorial.

Tests were performed on a XenServer 6.0.2 guest Debian 6 Squeeze 64 bit.
There was no significant difference when enabling HDD Write Back Cache in IMS management module.

xvda – Intel 320 SSD RAID1
xvdb – Seagate Savvio 10K.5 ST9900805SS SAS RAID1

 
hdparm:

# hdparm -tT /dev/xvda
/dev/xvda:
Timing cached reads: 13578 MB in 1.99 seconds = 6824.44 MB/sec
Timing buffered disk reads: 1422 MB in 3.00 seconds = 473.73 MB/sec
# hdparm -tT /dev/xvdb
/dev/xvdb:
Timing cached reads: 13618 MB in 1.99 seconds = 6844.60 MB/sec
Timing buffered disk reads: 1322 MB in 3.00 seconds = 440.17 MB/sec

 

seeker.py:

# ./seeker.py /dev/xvda
Benchmarking /dev/xvda [10.00 GB]
10/0.00 = 3310 seeks/second
0.30 ms random access time
100/0.02 = 5053 seeks/second
0.20 ms random access time
1000/0.18 = 5635 seeks/second
0.18 ms random access time
10000/1.82 = 5498 seeks/second
0.18 ms random access time
100000/17.14 = 5834 seeks/second
0.17 ms random access time
# ./seeker.py /dev/xvdb
Benchmarking /dev/xvdb [20.00 GB]
10/0.00 = 2529 seeks/second
0.40 ms random access time
100/0.01 = 8396 seeks/second
0.12 ms random access time
1000/0.13 = 7611 seeks/second
0.13 ms random access time
10000/1.16 = 8620 seeks/second
0.12 ms random access time
100000/11.25 = 8890 seeks/second
0.11 ms random access time

 

fio:

# cat random-read-test-xvda.fio
[random-read]
rw=randread
size=128m
directory=/tmp
# fio random-read-test-xvda.fio
random-read: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
Starting 1 process
random-read: Laying out IO file(s) (1 file(s) / 128MB)
Jobs: 1 (f=1): [r] [100.0% done] [7000K/0K /s] [1709/0 iops] [eta 00m:00s]
random-read: (groupid=0, jobs=1): err= 0: pid=11333
  read : io=131072KB, bw=7277KB/s, iops=1819, runt= 18012msec
    clat (usec): min=6, max=6821, avg=541.36, stdev=112.69
    bw (KB/s) : min= 6552, max=10144, per=100.18%, avg=7289.37, stdev=840.90
  cpu          : usr=0.44%, sys=6.86%, ctx=32882, majf=0, minf=24
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w: total=32768/0, short=0/0
     lat (usec): 10=0.01%, 250=0.01%, 500=17.30%, 750=81.96%, 1000=0.66%
     lat (msec): 2=0.05%, 4=0.01%, 10=0.01%

Run status group 0 (all jobs):
   READ: io=131072KB, aggrb=7276KB/s, minb=7451KB/s, maxb=7451KB/s, mint=18012msec, maxt=18012msec

Disk stats (read/write):
  xvda: ios=32561/3, merge=0/7, ticks=17340/0, in_queue=17340, util=96.44%
# cat random-read-test-xvdb.fio
[random-read]
rw=randread
size=128m
directory=/home
# fio random-read-test-xvdb.fio
random-read: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
Starting 1 process
random-read: Laying out IO file(s) (1 file(s) / 128MB)
Jobs: 1 (f=1): [r] [100.0% done] [6688K/0K /s] [1633/0 iops] [eta 00m:00s]
random-read: (groupid=0, jobs=1): err= 0: pid=11525
  read : io=131072KB, bw=7050KB/s, iops=1762, runt= 18592msec
    clat (usec): min=252, max=36782, avg=558.96, stdev=289.86
    bw (KB/s) : min= 5832, max= 9416, per=100.13%, avg=7057.95, stdev=733.93
  cpu          : usr=0.90%, sys=6.39%, ctx=32905, majf=0, minf=24
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w: total=32768/0, short=0/0
     lat (usec): 500=19.77%, 750=79.20%, 1000=0.79%
     lat (msec): 2=0.19%, 4=0.02%, 10=0.02%, 20=0.01%, 50=0.01%

Run status group 0 (all jobs):
   READ: io=131072KB, aggrb=7049KB/s, minb=7219KB/s, maxb=7219KB/s, mint=18592msec, maxt=18592msec

Disk stats (read/write):
  xvdb: ios=32447/38, merge=0/4, ticks=17836/1012, in_queue=18848, util=96.56%
# cat random-read-test-aio-xvda.fio
[random-read]
rw=randread
size=128m
directory=/tmp
ioengine=libaio
iodepth=8
direct=1
invalidate=1
# fio random-read-test-aio-xvda.fio
random-read: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=8
Starting 1 process
Jobs: 1 (f=1): [r] [100.0% done] [33992K/0K /s] [8299/0 iops] [eta 00m:00s]
random-read: (groupid=0, jobs=1): err= 0: pid=12384
  read : io=131072KB, bw=37567KB/s, iops=9391, runt=  3489msec
    slat (usec): min=5, max=65, avg= 9.79, stdev= 1.79
    clat (usec): min=427, max=42452, avg=833.25, stdev=714.35
    bw (KB/s) : min=31520, max=42024, per=101.20%, avg=38017.33, stdev=4144.75
  cpu          : usr=6.19%, sys=12.39%, ctx=29265, majf=0, minf=32
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=100.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.1%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w: total=32768/0, short=0/0
     lat (usec): 500=2.48%, 750=42.14%, 1000=38.11%
     lat (msec): 2=16.97%, 4=0.19%, 10=0.08%, 50=0.02%

Run status group 0 (all jobs):
   READ: io=131072KB, aggrb=37567KB/s, minb=38468KB/s, maxb=38468KB/s, mint=3489msec, maxt=3489msec

Disk stats (read/write):
  xvda: ios=32017/0, merge=5/6, ticks=26760/0, in_queue=28344, util=96.71%
# cat random-read-test-aio-xvdb.fio
[random-read]
rw=randread
size=128m
directory=/home
ioengine=libaio
iodepth=8
direct=1
invalidate=1
# fio random-read-test-aio-xvdb.fio
random-read: (g=0): rw=randread, bs=4K-4K/4K-4K, ioengine=libaio, iodepth=8
Starting 1 process
Jobs: 1 (f=1): [r] [75.0% done] [43073K/0K /s] [11K/0 iops] [eta 00m:01s]
random-read: (groupid=0, jobs=1): err= 0: pid=12464
  read : io=131072KB, bw=41783KB/s, iops=10445, runt=  3137msec
    slat (usec): min=7, max=409, avg=11.79, stdev= 3.66
    clat (usec): min=274, max=1464, avg=745.43, stdev=141.13
    bw (KB/s) : min=40416, max=42096, per=99.99%, avg=41777.33, stdev=668.21
  cpu          : usr=1.40%, sys=21.94%, ctx=27542, majf=0, minf=32
  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=100.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.1%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued r/w: total=32768/0, short=0/0
     lat (usec): 500=2.23%, 750=49.39%, 1000=46.19%
     lat (msec): 2=2.19%

Run status group 0 (all jobs):
   READ: io=131072KB, aggrb=41782KB/s, minb=42785KB/s, maxb=42785KB/s, mint=3137msec, maxt=3137msec

Disk stats (read/write):
  xvdb: ios=30272/0, merge=0/0, ticks=22772/0, in_queue=22772, util=96.17%

SSD performance should be much better than SAS but is not outperforming it.

I guess this might be a controller limitation.

Please comment about your experience with IMS disk performance.

One thought on “Intel Modular Server SSD and SAS disk performance”

  1. Just testing the Intel 520 SSDs in a raid10 vs. Toshiba 600GB disks in raid5. The SSDs should perform much better, but do not. About 10-20% performance gain max…

    Cheers,
    Björn

    Reply

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