VK Cloud Disk Performance

Various types of disks are used in the data storage system on the VK Cloud platform:

• HDD;
• SSD;
• High-IOPS SSD;
• Low Latency NVME.

Read more in the article Cloud Servers overview.

Certain performance characteristics are guaranteed for each type of disk.

Detailed performance characteristics for network HDDs of different sizes:

Detailed performance characteristics for network SSD of different sizes:

Detailed performance characteristics for network High-IOPS SSD of different sizes:

Detailed performance characteristics for local Low Latency NVME of different volumes:

1. Before testing, make sure that the following conditions are met:

   • the disk is non-bootable;
   • there is no load on the disk from the operating system.

   When these conditions are met, the IOPS measurement results must correspond to the following values:

   Type of testing	Result, IOPS
   Read/write in blocks of 4 KB in 32 threads	Complies with SLA
   Read/write in blocks of 8 KB in 32 threads	At least 75% of SLA
   Read/write in blocks of 16 KB in 32 threads	At least 50% of the SLA

2. Test the disk.

   Windows

   Linux

   To measure IOPS when reading and writing, use the DiskSpd or FIO utilities.

   DiskSpd

   1. Run the command prompt as an administrator.

   2. Create a temp directory and an empty file of at least 10 GB in size:

      Copy
      md C:\tempfsutil file createnew C:\temp\test.bin 10485760000

   3. Download the utility and unpack to the desired directory.

   4. Go to the amd64 directory of the unpacked utility.

   5. Run the command diskspd with parameters corresponding to the type of test:

      • -w — percentage of write operations, -w0 for the reading test, -w100 for the recording test;
      • -b — block size in bytes.

      Detailed description of all command parameters diskspd — in official documentation.

      • Random write test in blocks of 4 KB:

        Copy
        diskspd -Suw -b4K -o1 -t32 -r -w100 C:\temp\test.bin > C:\temp\random_write_results.txt

      • Random reading test in blocks of 4 KB:

        Copy
        diskspd -Suw -b4K -o1 -t32 -r -w0 C:\temp\test.bin > C:\temp\random_read_results.txt

   FIO

   1. Download and install FIO.

   2. Run the fio command with the parameters corresponding to the type of test:

      • --rw — randread or randwrite.
      • --bs — block size.
      • --filename — name of the test file.
      • --rate_iops — IOPS target value (optional). Use this parameter to get a more accurate latency value when testing the IOPS target value.

      Detailed description of all command parameters — in FIO documentation.

      • Random write test in blocks of 4 KB:

        PowerShell

        Command line

        Copy
        fio `   --name=randwrite `   --iodepth=32 `   --rw=randwrite `   --bs=4k `   --direct=1 `   --size=10G `   --numjobs=1 `   --runtime=240 `   --group_reporting `   --filename=C:\Users\ADMIN\test

      • Random reading test in blocks of 4 KB:

        PowerShell

        Command line

        Copy
        fio `   --name=randread `   --iodepth=32 `   --rw=randread `   --bs=4k `   --direct=1 `   --size=10G `   --numjobs=1 `   --runtime=240 `   --group_reporting `   --filename=C:\Users\ADMIN\test

3. If, when all conditions are met, the test results do not match the specified values, contact technical support.