• Configuring pools

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    Configuring pools

    Overview of creating pools

    Pools can be homogeneous or heterogeneous. All disks in a homogeneous pool have the same disk type, such as SAS disks. Disks in a heterogeneous pool have a mixture of disk types, such as a mixture of NL-SAS, SAS, and SAS Flash 2 disks. All supported disk types can be included in a heterogeneous pool except for SAS Flash 3 disks.

    Once you create a pool, you cannot reconfigure the pool's disks without deleting the storage resources configured in the pool and the pool itself. However, you can add disks to expand the pool.

    You can create pools in both physical and virtual deployments.

    Creating pools in physical deployments
    Create pools in physical deployments by specifying the following information:
    • RAID configuration for each tier. You can use the default RAID configuration, select a non-default RAID configuration, or select the Maximum Capacity option. Selecting the Maximum Capacity option enables the system to achieve a more efficient use of disks. The system can mix stripe widths to achieve this efficiency.
    • Number and type of disks to use in the pool. You can create a multi-tier pool if the system has multiple disk types.
    • Whether the pool will be able to use the FAST Cache, if the FAST Cache license is installed and the system has available SAS Flash 2 disks to support the FAST Cache.
    • Capability profile for use by VMware VVols, and usage tags for that profile (optional).

    When configuring a pool in physical deployments, you must specify a multiple of the preferred disk count for each tier you select. For example, when using RAID 5 4+1, you can specify a disk count of 5, 10, or 15, and so forth. It is also best to maintain the same capacity and rotational speed of all disks within a single tier of a given pool.

    Creating pools in virtual deployments

    Create pools in virtual deployments by specifying the following information:

    • Tier to use in the pool. You can create a multi-tier pool if the system has multiple underlying disk types.
    • Virtual disks to use in the pool for each included tier.
    • Capability profile for use by VMware VVols, and usage tags for that profile (optional).

    Create a pool in physical deployments

    Before you begin
    • Find out whether the storage system is licensed for FAST Cache. To do this, select the Settings icon, and then select Storage Configuration > FAST Cache. If the storage system is licensed for FAST Cache, you can choose whether to use it for the pool.
    • Decide whether to add new tiers to the pool and whether to change the RAID type of the new and assigned tiers.
    • Decide whether to create a capability profile that has capabilities based on the pool configuration. To use the capability profile for VMware VVols, you must assign specific usage tags, which are propagated to the VMware vSphere environment, and can be used in policy profiles. The virtualization administrator and storage administrator should work together to define these tags.
    You cannot shrink a pool or change its storage characteristics without deleting the storage resources configured in the pool and the pool itself. However, you can add disks to expand the pool.
    Procedure
    1. Under Storage, select Pools.
    2. Select the Add icon.
    3. Follow the steps in the wizard, taking into account the following considerations:
      • On the Tiers screen, you can only select multiple storage tiers if the system is licensed to use FAST VP. The wizard displays a usable capacity for each selected tier, which it calculates based on the RAID configuration and spare disk policy. You can optionally change the RAID configuration for selected tiers.
      • The number and types of disks you can choose is also based on the RAID configuration and spare disk policy.

    Create a pool in virtual deployments

    Before you begin

    From the storage administrator, obtain information about the underlying characteristics of the disks to use in the pool. You will use this information to assign tiers to the virtual disks that do not already have them assigned.

    Decide whether to create a capability profile for VMware VVols that has capabilities based on the pool configuration. To use the capability profile, you must assign specific usage tags, which are propagated to the VMware vSphere environment, and can be used in policy profiles. The virtualization administrator and storage administrator should work together to define these tags.

    You cannot shrink a pool or change its storage characteristics without deleting the storage resources configured in the pool and the pool itself. However, you can add disks to expand the pool.
    Procedure
    1. Under Storage, select Pools.
    2. Select the Add icon.
    3. Select the tiers and virtual disks to use in the pool. Each virtual disk must have an assigned tier. If the virtual disks you want to include in the pool do not have assigned tiers, you must assign one. The tier you select for a disk must be based on the underlying disk characteristics.
    4. Optionally create a VMware capability profile for use by VVols, and specify usage tags for that profile.

    Enable automatic snapshot deletion for a pool

    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and click the Edit icon.
    3. Select the Snapshot Settings tab.
    4. In the Automatically delete oldest snapshots section, select whether you want the automatic deletion to occur when the total pool consumption space reaches a threshold you set, snapshot pool consumption space reaches a threshold you set, or both. For each option, you can also set the threshold when the automatic snapshot deletion stops.

    Monitor pool space allocation and usage

    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and then select the Edit icon.
    3. Select Usage > Capacity to view pool space usage with the following metrics: current pool capacity, snapshot space used, subscribed space used, alert threshold, and a graph showing the pool's used capacity over time.
      • The subscribed space used is the percentage of the pool's total space that has been requested by its associated storage resources. When this value is over 100%, the pool is oversubscribed.
      • The alert threshold is the percentage of storage allocation at which Unisphere generates notifications about the amount of space remaining in the pool. You can set this value between 50% and 84%.
    4. Select Storage Resources to view a list of storage resources in the pool, along with the following metrics: total amount of pool space used by each resource and amount of pool space used for each resource's snapshots.

    View spare disk information

    Procedure
    1. Select the Settings icon, and then select Storage Configuration > Spare Disks to view the information about the spare disks in the storage system.
      For physical deployments this includes the status, name, type, capacity, and rotational speed (or Flash type for Flash disks) for each disk used in the spare disk policy. For virtual deployments, this includes the size and WWN of the virtual disks that are available for use in a pool. Disks that are already used in a pool or that are faulted are not included in the list.
    2. In physical deployments, select the Settings icon, and then select Storage Configuration > Spare Disk Policy to view the following information for each disk type/capacity/rotational speed or Flash type combination: Total number of disks in the system, number of unused disks that are available for use, and number of disks kept unused, because they are in the spare disks policy.

    Change pool properties

    Procedure
    1. Under Storage, select Pools.
    2. Select the relevant pool, and then select the Edit icon.
    3. On the General tab, optionally change the pool name and description.
    4. On the Disks tab, review the characteristics of the disks in the pool.
    5. On the Usage tab, select Capacity to view the amount of free space in the pool, subscribed pool capacity, and pool used capacity history. You can also change the alert threshold.
      • The subscribed space used is the percentage of the pool's total space that has been requested by its associated storage resources. When this value is over 100%, the pool is oversubscribed.
      • The alert threshold is the percentage of storage allocation at which Unisphere generates notifications about the amount of space remaining in the pool. You can set this value between 50% and 84%.

      Select Storage Resources to view the total space used by storage resources and snapshots. You can also delete pool snapshots.

    6. On the FAST VP tab (which appears if FAST VP is licensed), view data relocation and tier information for the pool. You can also exclude the pool from data relocations, manually start or stop data relocations for the pool, and manually move data to different tiers. Click Manage FAST VP settings to manage system-wide FAST VP settings.
    7. On the Snapshot Settings tab, review and optionally change the properties for snapshot automatic deletion.

    Expand a pool in physical deployments

    Expand a pool by adding disks to the pool.
    Procedure
    1. Under Storage, select Pools.
    2. Select the pool to expand, and then select Expand Pool.
    3. On the Storage Tiers tab, select the storage tiers for the disks you want to add to the pool. You can optionally change the RAID characteristics of each tier you select:
      • If you are adding disks to an existing tier, you can change the stripe width, but not the RAID type of the disks.
      • If you are adding a new tier to the pool, you can select a different RAID configuration for the disks in the tier.
    4. On the Disks tab, select the number of disks per tier to add to the pool.

    Expand a pool in virtual deployments

    Expand a pool by adding disks to the pool. Before you expand a pool, obtain information from your storage administrator about the underlying characteristics of the disks to use in the pool.
    Procedure
    1. Under Storage, select Pools.
    2. Select the pool to expand, and then select Expand Pool.
    3. On the Assign Tier to the Virtual Disk page, assign or optionally change the storage tiers to which virtual disks are assigned. To do this, select the virtual disk, select the Edit icon, and then select the tier.
    4. On the Tiers page, select one or more tiers to add to the pool.
    5. On the Virtual Disks page, select the virtual disks to add to the pool.

    Delete a pool

    You can delete pools if they contain no allocated storage resources, including consistency groups, LUNs, file systems, VMware datastores, or NAS servers.

    Procedure
    1. Under Storage, select Pools.
    2. Select the pool to delete, and click the Delete icon.