How to Measure Disk IOPS Values

One of the HW resources that can have a high impact on IBM Automatic Data Lineage performance is the disk (HDD / SSD / RAMDisk) and it’s performance. Recommendations for disk performance (available in IBM Automatic Data Lineage Technical Requirements) are specified using IOPS (Input Output operations Per Second). This storage device characteristic has to be measured; it is not an attribute of the storage device (disk). This how-to article describes how to measure this value.

This article describes the process on Unix-like operation systems, but the same approach can also be used on Windows.

This article describes how to utilize the open-source tool FIO ( https://fio.readthedocs.io/en/latest/) to perform the measurement, but there are also other tools with similar functionalities.

Instructions

  1. Download the FIO binaries, or build FIO binaries from the source code for your OS (https://fio.readthedocs.io/en/latest/fio_doc.html#binary-packages).

  2. Open an SSH connection to the server that has the filesystem whose performance should be tested mounted.

  3. Change the working directory to the location where the FIO binaries are.

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

  5. Once the test finishes, a similar output should be shown. The number of read operations per second can be found on the second line of this example (iops=47779). The number of write operations per second can be found on the third line of this example ( iops=15897). 

    test: (groupid=0, jobs=1): err= 0: pid=32210: Wed Mar 13 16:16:04 2019
  read : io=3073.4MB, bw=191118KB/s, iops=47779 , runt= 16467msec
  write: io=1022.7MB, bw=63592KB/s, iops=15897 , runt= 16467msec
  cpu          : usr=21.29%, sys=69.69%, ctx=8450, majf=0, minf=4
  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    : total=r=786784/w=261792/d=0, short=r=0/w=0/d=0