3/18/2023 0 Comments Artoon pirn![]() ![]() The results for each thread should be very similar in most cases. These results are broken out for each thread (four in our case), with separate sections in the results for Total IO, Read IO, and Write IO. You get the total bytes, total I/Os, MB/second, I/O per second (IOPS), and your average latency in milliseconds. The more interesting part of the test results comes next. ![]() The CPU section shows the CPU utilization for each logical processor, including user and kernel time, for the test interval. Next, the test results are shown starting with the actual test time, thread count, and logical processor count. ![]() The first section of the results gives you the exact command line that was used for the test, then specifies all of the input parameters that were used for the test run (which include the default values that may not have been specified in the actual command line). Here are what the results look like for this particular test run on my workstation. By default this will be a simple text summary in a text file using the file name that you specified, which will be in the same directory as the diskspd executable. When the test finishes, DiskSpd will provide a description of the test and the detailed results. Running the test starts with a default five second warm up time (before any measurements actually start), and then the actual test will run for the specified duration in seconds with a default cool down time of zero seconds. This is a pretty good set of parameters for a SQL Server OLTP workload.įigure 1: Example command line for DiskSpd It will save the results of the test to a text file called DiskSpeedResults.txt. It will use eight worker threads, each with four outstanding I/Os and a write entropy value seed of 1GB. This example command line will run a 30 second random I/O test using a 20GB test file located on the T: drive, with a 25% write and 75% read ratio, with an 8K block size. Here is an example command line:ĭiskspd –b8K –d30 –o4 –t8 –h –r –w25 –L –Z1G –c20G T:\iotest.dat > DiskSpeedResults.txt You will also want to specify the test file location and the file name for the results at the end of the line. Table 1: Basic command line parameters for DiskSpd Used to supply random data for writes, which is a good idea for SQL Server testingĬapture latency information during the test, which is a very good idea for testing SQL ServerĬreates workload file(s) of the specified size, specified as (K/M/G) Workload test write source buffer size, specified as (K/M/G). For example, –w25 means 25% writes, 75% reads If –r is used random tests are done, otherwise sequential tests are done Outstanding I/Os (meaning queue depth) per target, per worker threadĭisable software caching at the operating system level and hardware write caching, which is a good idea for testing SQL Server Tests of 30-60 seconds are usually long enough to get valid results For example –b8K means an 8KB block size, which is relevant for SQL Server Here are some of the command line parameters that you will want to start out with: Parameterīlock size of the I/O, specified as (K/M/G). Once you have the diskspd.exe executable file available, you will need to open a command prompt with administrative rights (by choosing “Run as Administrator”), and then navigate to the directory where you copied the diskspd.exe file. In most cases you will want the 64-bit version of DiskSpd from the amd64fre folder. To make things easier, I always copy the desired diskspd.exe executable file from the appropriate executable folder (amd64fre, armfre or x86fre) to a short, simple path like C:\DiskSpd. In order to do this, you’ll need to download and unzip DiskSpd. Now, we are going to dive a little deeper into how to actually use Microsoft DiskSpd to test your storage subsystem without using CrystalDiskMark 4.0. It is extremely useful for synthetic storage subsystem testing when you want a greater level of control than that available in CrystalDiskMark. DiskSpd provides the functionality needed to generate a wide variety of disk request patterns, which can be very helpful in diagnosis and analysis of I/O performance issues with a lot more flexibility than older benchmark tools like SQLIO. CrystalDiskMark was recently rewritten to use Microsoft DiskSpd for its testing, which makes it an even more valuable tool for your initial storage subsystem testing efforts. Previously, I covered the basics of storage subsystem metrics and testing in my article Analyzing I/O Subsystem Performance for SQL Server, including an introduction of CrystalDiskMark 4.0. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |