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Creating a QoS Policy

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Creating a QoS Policy in 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. In the General tab:

    • Enter a name for the QoS policy in the Name field.

    • Select the QoS policy type:

      • If you are going to create a QoS policy for views or block volumes, choose View or Volume respectively and proceed to step 4.

        Note

        Block storage QoS cannot be set by creating a view QoS policy for a Block-enabled view.

      • If you are creating a QoS policy for users, choose User and proceed to step 5.

      Depending on your choice, either View , Volume, or User tab is now available, where you can make further settings.

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

    • Select a tenant in the Tenant field to associate the QoS policy with a tenant.

    • (For view QoS policies only) If you want to prioritize the workloads served under this QoS policy, set the Prioritize policy over cluster or tenant limitations flag.

    • In Limit QoS by, leave Read/Write (default) to be able to set different QoS limits per operation type (one for reads and another for writes), or select Total if you want to set QoS limits that cap the total amount of read, write and metadata operations.

    • Under Static Performance Limits, specify static QoS limits per view or volume.

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

      • Select an appropriate unit of measurement.

      • To restrict the bandwidth and/or IOPS, fill in the fields following the BW and/or IOPS column respectively:

        1. Enter the maximum allowed bandwidth in the Max field.

          The Credit field will automatically be filled by the recommended credits value (which is the maximum limit multiplied by 4).

        2. If you want to modify the recommended values for credits and/or bursts, unselect the Use best practice option below the limit grid and enter the desired value(s) in the fields:

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

          • Credit. The maximum amount of bandwidth/IOPS credits that can be accumulated.

    • Under Capacity Limits, specify capacity-based QoS limits per unit of used or provisioned logical capacity.

      • Choose whether you want to limit Used Capacity or Provisioned Capacity.

        Note

        Leaving the default value of None means no capacity-based limits are used.

      • Enter the limits in the fields below.

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

        • Read BW per GB. Maximum read bandwidth (in MB/s) to provision per GB of used or provisioned logical capacity.

        • Read IOPS per GB. Maximum read IOPS to provision per GB of used or provisioned logical capacity.

        • Write BW per GB. Maximum write bandwidth (in MB/s) to provision per GB of used or provisioned logical logical capacity.

        • Write IOPS per GB. Maximum write IOPS to provision per GB of used or provisioned logical capacity.

    Note

    For volumes that share the same subsystem, ensure that all of the subsystem volumes have the same QoS limits set, or all of them do not have a QoS policy assigned, to prevent possible host IO performance impact.

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

    • Determine the scope of the user QoS policy:

      • Set Use as default QoS policy if you want the policy to apply to all users under the tenant specified in the Tenant field.

      • Select Users or IAM Roles to attach the policy to individual users or IAM roles. In the pane that opens:

        1. Select a tenant in the Tenant field.

        2. In the User or IAM Role field, choose User or IAM Role.

        3. Start typing a user name in the Select users or Select IAM roles field to look up and auto-populate users or IAM roles. Select an entry in the dropdown and click Add User or Add Role to add the entry to the list of users below.

    • Under Static Performance Limits, specify static QoS limits for user(s):

      • Select an appropriate unit of measurement in the Units field,

      • Enter the limits in the fields below.

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

        • To restrict the bandwidth, fill in the fields following the BW column, separately for Read and Write operations:

          • Max. The maximum allowed bandwidth.

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

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

        • To restrict the amount of IOPS, fill in the fields following the IOPS column, separately for Read and Write operations:

          • Max. The maximum allowed IOPS.

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

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

        • Under S3 Client Connections Limits, optionally click Set Manually and enter the maximum allowed number of S3 connections in the S3 Maximum Connections field. if you do not want to restrict the number of S3 connections per user, use the default of Unlimited.

  6. Click Create.

    The QoS policy is created and can be assigned to views or users respectively.

Creating a QoS Policy in VAST CLI

To create a view QoS policy:

To create a volume 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.