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Disk Performance Tool

Disk Performance tool (CVDiskPerf) can be used to test the performance of read, write operations on a disk to evaluate if the disk meets the IO requirements specified in Hardware Specifications for MediaAgents.

When you run this tool, you can specify the following settings:

  • Read and write modes, such as sequential or random access.

  • Parameters, such as block size for a file system or block count or file count or thread count.

For a disk volume as a mount path of a disk library, use the following default parameters to ensure that the average read throughput of the disk is approximately 600 GB per hour and the average write throughput of the disk is approximately 700 GB per hour.

  • BLOCKSIZE of 65536, BLOCKCOUNT of 16384, THREADCOUNT of 6 (each thread uses 1 file of 1 GB) and FILECOUNT of 6.

To determine optimal performance of a disk, calculate the average read and write throughputs from multiple samples.

The following table is a sample of the disk performance calculation:

Disk Performance

Throughput in GB/Hour

Write

Read

Sample 1

728.74

956.34

Sample 2

758.17

850.54

Sample 3

732.03

750.12

Average

739.64

852.33

Testing Read and Write Operations on a Disk

To test the performance of the read and write operations:

  1. From the command prompt go to the software_installation_directory/Base folder, and run the following command.

    Syntax

    The parameters used in this tool are case-sensitive. Parameters within [] are optional and default will be used if not given.

    • Windows

      CVDiskPerf -PATH <path to be tested> [-SEQUENTIAL] [-STAT] [-OUTFILE <report-file>] [-BLOCKSIZE <size in bytes>] [-BLOCKCOUNT <count>] [-FILECOUNT <count>] [-THREADCOUNT <count>] [-USERNAME <user name>] [-DOMAIN <domain name>] [-PASSWORD <password>]

    • UNIX/Linux

      ./CVDiskPerf -PATH <path to be tested> [-SEQUENTIAL] [-STAT] [-OUTFILE <report-file>] [-BLOCKSIZE <size in bytes>] [-BLOCKCOUNT <count>] [-FILECOUNT <count>] [-THREADCOUNT <count>] [-USERNAME <user name>] [-DOMAIN <domain name>] [-PASSWORD <password>]

      You can use the following parameters when you run the tool.

      Parameters

      Description

      -PATH

      The mount path that is tested for performance.

      -SEQUENTIAL

      (Optional). Measures sequential read and write operations.

      By default, random (-RANDOM) read and write operations are measured.

      -STAT

      (Optional). Measures the time taken to read the file information such as creation time of a file, file name and so on.

      -OUTFILE

      (Optional). The location of the output file that stores the disk performance results.

      Default: '.\CvDiskPerf.txt'.

      By default, the output file CvDiskPerf.txt is created in the same directory as the one where the Disk Performance tool is available.

      -BLOCKSIZE

      (Optional). The buffer size that is used to perform a single read or write operation.

      Default: 65536 bytes.

      -BLOCKCOUNT

      (Optional). The total number of blocks written to a file or read from a file.

      Default: 16384.

      -FILECOUNT

      (Optional). The number of files in the read and write operations.

      Default: 6.

      -THREADCOUNT

      (Optional). The number of threads used to perform read or write operations in parallel.

      Default: 6.

      -USERNAME, -PASSWORD, and -DOMAIN

      (Optional). User credentials that impersonate access to the path provided in the –PATH option.

      By default, the application user credentials are used. If the domain name is not provided, the default domain is used.

      -INSTANCE and -MOUNTPATHID

      (Optional) The instance name and mount path ID of the mount path. The values for -PATH, -USERNAME, -PASSWORD and -DOMAIN are not required as the system automatically collects this information.

Examples

  • To test the performance of a disk with default values, RANDOM, BLOCKSIZE = 65536, BLOCKCOUNT = 16384, FILECOUNT = 6, THREADCOUNT = 6.

    • Windows: 

      CVDiskPerf -PATH f:\Disk01

    • UNIX or Linux: 

      ./CVDiskPerf -PATH /vol/Disk01/

  • To test the performance of random read and write operations of a disk.

    • Windows: 

      CVDiskPerf -PATH f:\Disk01 -RANDOM -OUTFILE c:\temp\perfresult.txt

    • UNIX or Linux: 

      ./CVDiskPerf -PATH /vol/Disk01 -RANDOM -OUTFILE /root/temp/perfresult.txt

  • To test the performance of sequential read and write operations of a disk. This example limits the test using the parameters BLOCKSIZE - 512, FILECOUNT - 4, and THREADCOUNT - 10.

    • Windows: 

      CVDiskPerf -PATH f:\Disk01 -SEQUENTIAL -BLOCKSIZE 512 -FILECOUNT 4 -THREADCOUNT 5 -OUTFILE c:\temp\perfresult.txt

    • UNIX or Linux: 

      ./CVDiskPerf -PATH /vol/Disk01 -SEQUENTIAL -BLOCKSIZE 512 -FILECOUNT 4 -THREADCOUNT 5 -OUTFILE /root/temp/perfresult.txt

  • To test the performance of the read and write operations of a disk that is located on a network path. This example limits the test using the parameters FILECOUNT - 20 and THREADCOUNT - 10.

    • Windows: 

      CVDiskPerf -PATH \\networkpath\Disk01 -OUTFILE c:\temp\perfresult.txt -FILECOUNT 20 -THREADCOUNT 10 -USERNAME commuser –PASSWORD commpw

    • UNIX or Linux: 

      ./CVDiskPerf -PATH /vol/Disk01 -RANDOM -OUTFILE /root/temp/perfresult.txt -FILECOUNT 20 -THREADCOUNT 10

      Note: If the MediaAgent is a UNIX/Linux MediaAgent, To access an NFS share, you must mount the share to your UNIX/Linux MediaAgent. When the share is mounted, it appears as another local directory on the system. You can provide this directory location in the path.

  • To test the performance of the read and write operations of a local disk. This example limits the test using the parameters FILECOUNT = 20 and THREADCOUNT = 10.

    • Windows: 

      CVDiskPerf -PATH f:\Disk01 -RANDOM -FILECOUNT 20 -THREADCOUNT 10 -OUTFILE c:\temp\perfresult.txt

    • UNIX or Linux: 

      ./CVDiskPerf -PATH /vol/Disk01 -RANDOM -FILECOUNT 20 -THREADCOUNT 10 -OUTFILE /root/temp/perfresult.txt

Results

The details of the disk performance are stored in the output file specified in the -OUTFILE parameter. The following information is a sample of the contents of an output file performed on the Windows MediaAgent:

DiskPerf 2.0
 Creating Report CvDiskPerf.txt ...
 Creating folder c:\DISK_READ_TEST
 Creating files..
 Writing files..
 Reading files..
 Deleting files..
 DiskPerf Version : 2.0
 Path Used : f:\Disk01
 Read-Write type : RANDOM
 Block Size : 65536
 Block Count : 16384
 File Count : 6
 Thread Count : 6
 Total Bytes Written : 6442450944
 Total Bytes Read : 6442450944
 Total Bytes Deleted : 6442450944
 ----
 Time Taken to Create(S) : 28.66
 Time Taken to Write&flush(S): 29.64
 Flush alone : 28.44
 Time Taken to Read(S) : 0.77
 Time Taken to Delete(S) : 0.66
 ----
 Throughput Create(GB/H) : 753.77
 Throughput Write(GB/H) : 728.74
 Throughput Read(GB/H) : 925.78
 Throughput Delete(GB/H) : 32930.40

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