Benchmarking Disks on VPS: SSD, NVMe or HDD

Are you sure you are getting SSD when you rent a VPS? Here's how to make sure

sudo apt install fio

fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=random_read_write.fio --bs=4k --iodepth=64 --size=4G --readwrite=randrw --rwmixread=75 ; rm random_read_write.fio

The result would be something like this:

SSD:

test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=64

fio-3.16

Starting 1 process

test: Laying out IO file (1 file / 4096MiB)

Jobs: 1 (f=1): [m(1)][100.0%][r=83.7MiB/s,w=27.3MiB/s][r=21.4k,w=6993 IOPS][eta 00m:00s]

test: (groupid=0, jobs=1): err= 0: pid=1436574: Thu May 27 19:01:27 2021

  read: IOPS=18.2k, BW=70.0MiB/s (74.4MB/s)(3070MiB/43241msec)

   bw (  KiB/s): min=  456, max=130000, per=99.85%, avg=72589.30, stdev=36572.29, samples=86

   iops        : min=  114, max=32500, avg=18147.33, stdev=9143.07, samples=86

  write: IOPS=6074, BW=23.7MiB/s (24.9MB/s)(1026MiB/43241msec); 0 zone resets

   bw (  KiB/s): min=  176, max=42936, per=99.85%, avg=24259.07, stdev=12200.49, samples=86

   iops        : min=   44, max=10734, avg=6064.77, stdev=3050.12, samples=86

  cpu          : usr=3.35%, sys=13.20%, ctx=781969, majf=0, minf=10

  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, >=64=100.0%

     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=0.1%, >=64=0.0%

     issued rwts: total=785920,262656,0,0 short=0,0,0,0 dropped=0,0,0,0

     latency   : target=0, window=0, percentile=100.00%, depth=64

Run status group 0 (all jobs):

   READ: bw=70.0MiB/s (74.4MB/s), 70.0MiB/s-70.0MiB/s (74.4MB/s-74.4MB/s), io=3070MiB (3219MB), run=43241-43241msec

  WRITE: bw=23.7MiB/s (24.9MB/s), 23.7MiB/s-23.7MiB/s (24.9MB/s-24.9MB/s), io=1026MiB (1076MB), run=43241-43241msec

Disk stats (read/write):

  sdh: ios=782456/263158, merge=1293/2586, ticks=1838928/822350, in_queue=2134502, util=99.12%

HDD:

too slow (1MB/s would took about 40 minutes)

VPS:

test: (g=0): rw=randrw, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=libaio, iodepth=64

fio-3.16

Starting 1 process

test: Laying out IO file (1 file / 4096MiB)

Jobs: 1 (f=1): [m(1)][100.0%][r=11.2MiB/s,w=3924KiB/s][r=2873,w=981 IOPS][eta 00m:00s]

test: (groupid=0, jobs=1): err= 0: pid=3829977: Thu May 27 20:04:10 2021

  read: IOPS=3029, BW=11.8MiB/s (12.4MB/s)(3070MiB/259388msec)

   bw (  KiB/s): min= 7744, max=144776, per=99.95%, avg=12112.97, stdev=7631.07, samples=518

   iops        : min= 1936, max=36194, avg=3028.16, stdev=1907.77, samples=518

  write: IOPS=1012, BW=4050KiB/s (4148kB/s)(1026MiB/259388msec); 0 zone resets

   bw (  KiB/s): min= 2844, max=47936, per=99.94%, avg=4047.41, stdev=2504.77, samples=518

   iops        : min=  711, max=11984, avg=1011.83, stdev=626.19, samples=518

  cpu          : usr=2.89%, sys=10.00%, ctx=605914, majf=0, minf=8

  IO depths    : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=0.1%, 32=0.1%, >=64=100.0%

     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=0.1%, >=64=0.0%

     issued rwts: total=785920,262656,0,0 short=0,0,0,0 dropped=0,0,0,0

     latency   : target=0, window=0, percentile=100.00%, depth=64

Run status group 0 (all jobs):

   READ: bw=11.8MiB/s (12.4MB/s), 11.8MiB/s-11.8MiB/s (12.4MB/s-12.4MB/s), io=3070MiB (3219MB), run=259388-259388msec

  WRITE: bw=4050KiB/s (4148kB/s), 4050KiB/s-4050KiB/s (4148kB/s-4148kB/s), io=1026MiB (1076MB), run=259388-259388msec

Disk stats (read/write):

  sda: ios=785732/271244, merge=0/973, ticks=795112/15862499, in_queue=15747316, util=99.75

 

 Conclusion

If your VPS speed more than HDD on table below, it's a big possibility that it's using SSD, or at least RAID. But there's another possibility that they are throttling shared VPS so it wouldn't distrub other people's QoS.

 Update

comparison with local NVMe it would be something like this:

   read: IOPS=61.6k, BW=241MiB/s (252MB/s)(3070MiB/12752msec)
  write: IOPS=20.6k, BW=80.5MiB/s (84.4MB/s)(1026MiB/12752msec); 0 zone resets
   read: IOPS=40.2k, BW=157MiB/s (165MB/s)(3070MiB/19546msec)
  write: IOPS=13.4k, BW=52.5MiB/s (55.0MB/s)(1026MiB/19546msec); 0 zone resets

comparison with local HDD with bad sectors it would be something like this:

 

   read: IOPS=217, BW=868KiB/s (889kB/s)(23.6MiB/27852msec)
  write: IOPS=74, BW=296KiB/s (304kB/s)(8256KiB/27852msec); 0 zone resets

 

comparison with vps that claimed to be SSD it would be something like this:

 

   read: IOPS=2908, BW=11.4MiB/s (11.9MB/s)(289MiB/25446msec)
  write: IOPS=965, BW=3861KiB/s (3954kB/s)(95.9MiB/25446msec); 0 zone resets

   read: IOPS=3182, BW=12.4MiB/s (13.0MB/s)(1728MiB/139002msec)
  write: IOPS=1066, BW=4268KiB/s (4370kB/s)(579MiB/139002msec); 0 zone resets