Creating a SmartQoS Policy

Precautions

The user host aggregates I/Os for specific service models. As a result, the IOPS of services received by the storage system is lower than that delivered by the host application. If the IOPS upper limit in a QoS policy is set based on the IOPS of services delivered by the host application, the QoS policy cannot limit the IOPS of services on the storage system effectively. In this case, you can lower the IOPS upper limit or configure a bandwidth upper limit in the QoS policy.

Procedure

1. Choose Resources > Tuning > SmartQoS.
2. Select the desired account from the Account drop-down list in the upper left corner.
3. Click Create.

   The Create QoS Policy page is displayed.

4. Set a QoS policy name.
   

   • The name must be unique.
   • The name can only contain digits, letters, underscores (_), and hyphens (-), and must start with a digit or letter.
   • The name contains 1 to 63 characters.

5. Set basic parameters of the QoS policy in either of the following ways, including By performance density and upper limits and By read and write upper limits.
   • By performance density and upper limits

     Table 1 describes related parameters.

     Table 1 QoS policy parameters

     Parameter	Description
     Max. IOPS/GB	Indicates the maximum number of read/write operations that can be performed on an object per second per GB.
     Max. IOPS	Indicates the maximum number of read/write operations that can be performed on an object per second. NOTE: If the value of Max. IOPS/GB is greater than 0, calculate the effective maximum IOPS in the QoS policy as follows: Calculate (IOPS/GB x Object capacity) + 100. Compare the calculation result obtained in 1 with Max. IOPS. The smaller of the two values is the effective maximum IOPS. Suppose that Max. IOPS/GB is 2, object capacity is 100 GB, and Max. IOPS is 1000. The effective maximum IOPS in the QoS policy is 300 (that is, 2 x 100 + 100), because 300 is smaller than 1000. If Max. IOPS/GB is set to 0, the effective maximum IOPS in the QoS policy is Max. IOPS.
     Burst IOPS/Duration	Indicates the maximum number of read/write operations that can be performed on an object per second within a specified period when the burst function is enabled. Burst IOPS: indicates the maximum number of read/write operations that can be performed on an object per second when the burst function is enabled. NOTE: The burst function boosts the IOPS of an object within a specified period of time, temporarily improving object performance. The system compares the effective maximum IOPS for an object with the burst IOPS. If the effective maximum IOPS is smaller, the burst function is enabled. Burst duration: indicates the minimum period during which the burst function is enabled for an object.
     Max. MBPS/TB	Indicates the maximum amount of data that can be transmitted on an object per second per TB.
     Max. MBPS	Indicates the maximum amount of data that can be transmitted on an object per second. NOTE: If the value of Max. MPBS/TB is greater than 0, calculate the effective maximum MPBS in the QoS policy as follows: Calculate (MBPS/TB x Object capacity) + 5. Compare the calculation result obtained in 1 with Max. MBPS. The smaller of the two values is the effective maximum MBPS. Suppose that Max. MBPS/TB is 20, object capacity is 2 TB, and Max. MBPS is 100. The effective maximum MBPS in the QoS policy is 45 (that is, 20 x 2 + 5), because 45 is smaller than 100. If Max. MPBS/TB is set to 0, the effective maximum MPBS in the QoS policy is Max. MPBS.
     Burst MBPS/TB	Indicates the maximum amount of data that can be transmitted on an object per second per TB when the burst function is enabled. NOTE: The burst function boosts the amount of data that can be transmitted per second, temporarily improving object performance. Total bandwidth triggered for an object = Burst MBPS/TB x Volume capacity The system compares the effective maximum MBPS for an object with the total bandwidth triggered for the object. If the effective maximum MBPS is smaller, the burst function is enabled.

   • By read and write upper limits

     Table 2 describes related parameters.

     Table 2 QoS policy parameters

     Parameter	Description
     Max. Read IOPS	Indicates the maximum number of read operations that can be performed per second.
     Max. Write IOPS	Indicates the maximum number of write operations that can be performed per second.
     Max. Read MBPS	Indicates the maximum amount of data that can be read per second.
     Max. Write MBPS	Indicates the maximum amount of data that can be written per second.

6. Set a trigger policy for the QoS policy. Possible options are One-off, Daily, Weekly, and Always.
   • One-off: The QoS policy takes effect once at the specified time.
     1. In Start Date, set the date when the policy takes effect.
     2. In Start Time, set the time when the policy takes effect.
     3. In Duration, set the duration over which the policy remains in effect.
        

        The duration ranges from 30 minutes to 24 hours.

   • Daily: The QoS policy takes effect daily.
     1. In Start Date, set the date when the policy takes effect.
     2. In Start Time, set the time when the policy takes effect every day.
     3. In Duration, set the duration over which the policy remains in effect.
        

        The duration ranges from 30 minutes to 24 hours.

   • Weekly: The QoS policy takes effect weekly.
     1. In Start Date, set the date when the policy takes effect and the day when the policy takes effect every week.
     2. In Start Time, set the time when the policy takes effect every specified day of the week.
     3. In Duration, set the duration over which the policy remains in effect.
        

        The duration ranges from 30 minutes to 24 hours.

   • Always: The QoS policy remains in effect permanently.

7. Click OK.
8. Confirm your operation as prompted.