Creating a QoS Policy

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Creating a QoS Policy via VAST Web UI

  1. From the left navigation menu, select Element Store and then QoS Policies.

  2. Click + Create QoS Policy to open the  Add QoS Policy dialog.

  3. If you are going to create a QoS policy for a view, proceed to step 4. If you are creating a QoS policy for a user, go to the User tab and proceed to step 5.

  4. To create a QoS policy for a view, complete the fields in the View tab:

    Name

    Enter a name for the view QoS policy.

    Mode

    Select one of the QoS provisioning modes:

    • Static. Lets you set minimum and maximum static limits.

    • Used Capacity. Lets you set used capacity-based limits and maximum static limits.

    • Provisioned Capacity. Lets you set provisioned capacity-based limits and maximum static limits.

    For a detailed explanation of QoS limits and provisioning modes, see QoS Overview.Quality of Service Overview

    Limit By

    Select performance characteristic(s) by which to limit service:

    • BW and IOPS. Lets you set limits on both bandwidth (BW) and I/O per second (IOPS).

    • BW. Lets you set limits on bandwidth only.  

      Note

      When this option is selected, the fields for setting IOPS limits are inactive.

    • IOPS. Lets you set limits on IOPS only.

      Note

      When this option is selected, the fields for setting bandwidth limits are inactive.

    Capacity limits

    Specify capacity-based QoS limits per unit of used or provisioned logical capacity, depending on the provisioning mode. Units are stated per limit.

    • Read BW per GB. Maximum read bandwidth (in MB/s) to provision per GB of used or provisioned logical capacity, depending on the provisioning mode.

    • Read IOPS per GB. Maximum read IOPS to provision per GB of used or provisioned logical capacity, depending on the provisioning mode.

    • Write BW per GB. Maximum write bandwidth (in MB/s) to provision per GB of used or provisioned logical logical capacity, depending on the provisioning mode.

    • Write IOPS per GB. Maximum write IOPS to provision per GB of used or provisioned logical capacity, depending on the provisioning mode.

    For each of the limits , '0' means no limit is set.

    Static limits

    Specify static QoS limits per view. You can select the measurement unit for bandwidth limits from the Scale dropdown.

    • Under BW, for Read and/or Write operations:

      • Min. The minimum bandwidth to provision. This limit can only be set when Mode is Static.

      • Max. The maximum allowed bandwidth.

      • Burst. The maximum  burst  bandwidth that can be provided while there are accumulated bandwidth credits.

      • Credits. The maximum amount of bandwidth credits that can be accumulated.

    • Under IOPS, for Read and/or Write operations:

      • Min. The minimum IOPS to provision. This limit can only be set when Mode is Static.

      • Max. The maximum allowed IOPS.

      • Burst. The maximum  burst  IOPS that can be provided while there are accumulated IOPS credits.

      • Credits. The maximum amount of IOPS credits that can be accumulated.

    For each of the limits , '0' means no limit is set.

    Tip

    If Limit By is set to BW and IOPS, you must set a maximum limit for read IOPS to be equal to or greater than the maximum limit for read bandwidth.

  5. To create a QoS policy for one or more users, complete the fields in the User tab:

    Name

    Enter a name for the user QoS policy.

    Tenant

    Select a tenant to filter the list of users to which this user QoS policy can be assigned.

    Attached users

    Enter one or more users to which to assign the user QoS policy.

    You can add or update attached users only when Is default User QOS Policy is off.

    Limit By

    Select performance characteristic(s) by which to limit service:

    • BW and IOPS. Lets you set limits on both bandwidth (BW) and I/O per second (IOPS).

    • BW. Lets you set limits on bandwidth only.  

      Note

      When this option is selected, the fields for setting IOPS limits are inactive.

    • IOPS. Lets you set limits on IOPS only.

      Note

      When this option is selected, the fields for setting bandwidth limits are inactive.

    Is default User QoS Policy

    When enabled, the policy is used as the default user QoS policy for the tenant specified in the Tenant field.

    Caution

    Enabling this option resets the list of Attached users.

    Static limits

    Specify  static QoS limits for user(s):

    • Under BW, for Read and/or Write operations:

      • Min. The minimum bandwidth to provision. This limit can only be set when Mode is Static.

      • Max. The maximum allowed bandwidth.

      • Burst. The maximum  burst  bandwidth that can be provided while there are accumulated bandwidth credits.

      • Credits. The maximum amount of bandwidth credits that can be accumulated.

      You can select the measurement unit for bandwidth limits from the Scale dropdown.

    • Under IOPS, for Read and/or Write operations:

      • Min. The minimum IOPS to provision. This limit can only be set when Mode is Static.

      • Max. The maximum allowed IOPS.

      • Burst. The maximum  burst  IOPS that can be provided while there are accumulated IOPS credits.

      • Credits. The maximum amount of IOPS credits that can be accumulated.

    For each of the limits , '0' means no limit is set.

  6. Click Create.

    The policy is created and can be assigned to a view or to one or more users respectively.

Creating a QoS Policy via VAST CLI

To create a view QoS policy:

To create a user QoS policy:

  1. Run the qospolicy create command with --policy-type USER.

  2. Run the qospolicy attach-user command for the newly created QoS policy.