• Managing FAST VP

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    Managing FAST VP

    About FAST VP

    Fully Automated Storage Tiering for Virtual Pools (FAST VP) enables the system to retain the most frequently accessed or important data on fast, high-performance disks and move the less frequently accessed and less important data to lower-performance, cost-effective disks. FAST VP does the following for pools:

    • Monitors the usage of the data in a tiered pool. Tiered pools are heterogeneous pools that are configured with multiple classes of disks (SAS Flash 2 plus SAS and/or NL-SAS).
    • Depending on the tiering policy, uses the monitoring statistics to automatically relocate data chunks, at 256 MB granularity, to other tiers within the pool. For example, the Start High then Auto-Tier policy relocates data to the storage tier that is best suited for that data, based on relative activity.
    • Performs load balancing across the disks in tiered and non-tiered pools.

    FAST VP is an automated feature that optimizes disk utilization. It requires very little manual intervention.

    To configure and use the FAST VP feature, the FAST VP license must be installed on the system. FAST VP can use all supported disk types except for SAS Flash 3 disks. Not all models support FAST VP.

    The data relocation performed by FAST VP can help you achieve the following benefits:

    • Increased performance

      In some cases, you can double performance throughput by adding less than 10 percent of a pool's total capacity in SAS Flash 2 disks.

    • Reduced Total Cost of Ownership (TCO)

      Using a combination of NL-SAS, SAS, and SAS Flash 2 disks instead of all SAS disks enables you to address performance requirements and still reduce the disk count. In some cases, you can achieve up to a two-thirds reduction in disk count by using FAST VP.

    Data relocation with FAST VP

    Data relocation (also called auto-tiering) is the process by which the system relocates data to another tier within the same pool and rebalances data within a tier to achieve maximum pool performance gain. Data relocation can be scheduled or manually initiated.

    The data relocation process does the following:

    • Relocates the most active data up to the highest available tier.
    • Relocates the least active data to lower tiers, as needed to free up space for more active data in the higher tiers.
    • Rebalances data within a tier.
    Scheduled data relocation

    Scheduled data relocation is enabled for all pools by default when FAST VP is installed on your system. The system performs scheduled data relocations for pools participating in the automatic data relocation schedule. By default, the data relocation window is every day from 22:00 to 6:00 (UTC time) the next day. The specified data relocation times provide the window of time in which data relocations occur on an ongoing basis, if the system determines the relocations are needed.

    You can do the following to configure scheduled data relocations:

    • Disable or re-enable scheduled data relocations for the system.
    • Change the days on which data relocation occurs and the data relocation window start time and end time for each scheduled day.
    • Configure individual pools to participate in scheduled data relocations.
    • Pause all scheduled data relocations. (This action also pauses manual data relocations that are currently in progress.)
    • Resume all scheduled data relocations (This action also resumes paused manual data relocations whose specified end times have not expired.)
    The system rebalances data within a tier automatically when a pool tier is expanded.
    Manual data relocation

    You can manually initiate data relocations for individual pools. When you start a manual data relocation, you specify a data relocation rate and an end time for the data relocation operation.

    You can do the following to control manual data relocations:

    • Start or stop a manual data relocation.
    • Pause manual relocations that are currently in progress. This action also pauses all scheduled data relocations.
    • Resume paused manual relocations whose end times are not over. This action also resumes all scheduled data relocations.

    FAST VP tiering policy

    The following table describes the FAST VP tiering policy settings, which are defined at the data-resource level. This policy defines both the initial tier placement and the ongoing automated tiering of data during data relocation operations.

    Table 1. FAST VP tiering policy settings
    Tiering policy
    Corresponding initial tier placement
    Description
    Start High then Auto-Tier (default)
    Highest available tier
    Recommended setting. Sets the initial data placement to the highest-performing disks with available space, and then relocates portions of the storage resource's data based on I/O activity.
    Auto-Tier
    Optimize for pool performance
    Sets the initial data placement to an optimum, system-determined setting, and then relocates portions of the storage resource's data based on the storage resource's performance statistics such that data is relocated among tiers according to I/O activity.
    Highest Available Tier
    Highest available tier
    Sets the initial data placement and subsequent data relocation (if applicable) to the highest-performing disks with available space.
    Lowest Available Tier
    Lowest available tier
    Sets the initial data placement and subsequent data relocation (if applicable) to the most cost-effective disks with available space.

    Enable or disable scheduled data relocations at the system level

    When you disable scheduled data relocations at the system level, no pools in the system will participate in scheduled data relocations. If you disable scheduled data relocations at the system level when a data relocation is taking place, the system will complete the data relocation.

    When you enable scheduled data relocations at the system level, pools that have scheduled data relocations enabled at the pool level will participate in scheduled data relocations.

    Scheduled data relocations for the storage system are enabled by default.
    Procedure
    1. Select the Settings icon, and then select Storage Configuration > FAST VP.
    2. Do either of the following:
      • Select Pause to disable data relocations for the storage system.
      • Select Resume to enable data relocations for the storage system, and optionally select Modify data relocation schedule to change the data relocation schedule.

    Stop a pool from participating in scheduled data relocations

    If you stop a pool from participating in scheduled data relocations when a data relocation is taking place, the system will complete the data relocation.
    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and click the Edit icon.
    3. Select Fast VP.
    4. If the Data relocations scheduled field has a value of No, select the Edit icon, and select Yes on the confirmation message.

    Manually initiate or stop data relocations for a pool

    You can manually initiate or stop data relocations for pools.

    Procedure
    1. Under Storage, select Pools.
    2. Select the pool for which you want to initiate or stop data relocations, and then select the Edit icon.
    3. Select FAST VP.
    4. Do either of the following:
      • To start data relocations for the pool, choose Start Relocation, and select the rate and end time for the data relocation. A data relocation rate of Low has the least impact on system performance, Medium (the default) has a moderate impact on system performance, and High has the most impact on system performance.
      • To stop data relocations, choose Stop Relocation. This stops all data relocations for the pool, including manually initiated data relocations that are currently in progress and scheduled data relocations.

    Pause or resume data relocations for all pools

    Pausing data relocations stops all scheduled data relocations as well as manual data relocations that are in progress. Resuming data relocations restarts these data relocations.
    Procedure
    1. Select the Settings icon, and then select Storage Configuration > FAST VP.
    2. Pause or resume data relocations.

    Change system-level data relocation information

    System-level data relocation information includes whether scheduled relocations are enabled for the system. If scheduled data relocations are enabled, the information includes:

    • Total amount of data in the system scheduled to move to higher and lower tiers.
    • Total amount of data in the system to be rebalanced within a tier
    • Estimated time needed for the scheduled data relocations.
    Procedure
    1. Select the Settings icon, and then select Storage Configuration > FAST VP.
    2. Optionally, take one of the following actions:
      • Select Pause (if enabled) to pause all scheduled data relocations and manual data relocations that are currently in progress.
      • Select Resume (if enabled) to resume paused data relocations.
      • Modify the data relocation rate. A data relocation rate of Low has the least impact on system performance, Medium (the default) has a moderate impact on system performance, and High has the most impact on system performance.
      • Select Modify data relocation schedule to change the data relocation schedule.

    Change data relocation information for a pool

    You can specify whether a pool is scheduled to participate in scheduled data relocations. You can also manually start or stop data relocations on the pool.
    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and click Edit.
    3. Select FAST VP.
    4. Make the appropriate changes.

    View pool-level FAST VP information

    If a FAST VP license is installed on the system, you can view the following information for a pool:

    • Whether the pool participates in scheduled data relocations.
    • Estimated time needed for scheduled data relocations.
    • Start and end time for the most recent data relocation.
    • Number and type of disks in each tier.
    • Amount of data in the pool scheduled to move to higher and lower tiers.
    • Amount of data in the pool scheduled to be rebalanced within a tier.
    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and then select the Edit icon.
    3. Select the FAST VP tab.
    4. Optionally click Manage FAST VP system settings to view the data relocation rate.
      • Low has the least impact on system performance.
      • Medium (the default) has a moderate impact on system performance.
      • High has the most impact on system performance.