Modifying Capacity of a Storage Pool

Prerequisites

• The Health Status of the storage pool is Normal.
• The disk domain has available storage space for capacity expansion of the storage pool
• The reduced capacity must be smaller than maximum capacity for reduction.

Procedure

1. Choose Provisioning > Storage Pool.
2. Select the storage pool you want to expand and click Modify Capacity.

   The Modify Capacity dialog box is displayed.

3. In Operation, select the mode of modifying capacity. The modes are Expand capacity and Reduce capacity.
   • Expand the capacity of a storage pool.
     1. Select the storage tier you want to expand or create.
     2. You can create a new storage tier or expand the existing storage tier to expand storage pools.
        • To create a storage tier, configure the RAID policy and in Capacity, enter the capacity of the storage tier.
          Table 13-4 Storage tier parameters

          Parameter	Description
          RAID Policy	RAID level. The system supports RAID 0, RAID 1, RAID 10, RAID 3, RAID 5, RAID 50, and RAID 6. Select a RAID policy based on the service plan. The default RAID policy of a storage tier varies with the number of disks allocated to the storage tier. Details are as follows: If the number of disks allocated to a storage tier is smaller than 10: High-performance tier: RAID 10 Performance tier: RAID 5 (4D+1P) Capacity tier: RAID 6 (4D+2P) If the number of disks allocated to a storage tier is equal to 10: High-performance tier: RAID 10 Performance tier: RAID 5 (8D+1P) Capacity tier: RAID 6 (4D+2P) If the number of disks allocated to a storage tier is greater than 10: High-performance tier: RAID 10 Performance tier: RAID 5 (8D+1P) Capacity tier: RAID 6 (8D+2P) NOTE: RAID 0 can only be configured using the CLI. For details, see the command reference specific to your product model. You are advised to configure RAID 6 for the capacity tier to ensure data security. If the number of SSDs in a disk domain is two or three, you are advised to configure RAID 1 (2D) for the high-performance tier. The number of RAID data disks of different storage pool tiers must be a multiple of 1, 2, 4, or 8.
          Capacity	Capacity that the storage tier provides for the storage pool. Three capacity levels are provided: TB, GB, and PB. NOTE: If you select Use all available capacity, the storage system allocates all available capacity in this storage tier to the new storage pool. The capacity must be no larger than the available capacity of the storage tier.
          Enhanced RAID data protection (applicable to V500R007C70 and later versions)	After this option is selected, the storage system will evaluate whether the current data reliability meets the recommended requirements based on the disk type, disk quantity, single disk capacity, RAID level, and RAID member disk quantity in the current disk domain. The storage system automatically filters out RAID policies that do not meet the recommended data reliability requirements.

        • To expand a storage tier, in Added Capacity, enter the added capacity of the storage tier.
        • You can configure RAID policy only for new created storage tier. For the storage tier that already exists in the storage pool, you cannot modify its RAID policy.
        • The number of RAID data disks of different storage pool tiers must be a multiple of 1, 2, 4, or 8.
   • Reduce the capacity of a storage pool.
     1. Select the storage tier you want to reduce.
     2. In Reduction Capacity, enter the capacity of the storage tier to be reduced.

4. Optional: Configure a SmartTier policy for the storage pool being created.
   • If the storage pool consists of multiple storage tiers, you are advised to configure a SmartTier policy. The policy enables data to migrate among different storage tiers, optimizing storage performance.
   • Some product models do not support SmartTier. The actual GUIs prevail. To check whether your product model supports SmartTier, see its product description.
   1. Click Set SmartTier Policy.

      The Set SmartTier Policy dialog box is displayed. Table 13-5 describes the related parameters.

      Table 13-5 SmartTier policy parameters

      Parameter	Description	Setting
      Service Monitoring Period	Period of time during which the system monitors services and collects hot data statistics after you select Enable I/O monitoring. Data is migrated among storage tiers based on the statistics. You can specify the period by setting days, Start Time, and Duration.	[Default value] I/O monitoring disabled
      Data Migration Plan	Trigger policy of data relocation among storage tiers in a storage pool. The policies include: Manual: You must manually trigger data relocation among storage tiers. The data relocation process is transparent to application servers. Manual data relocation can be performed anytime. Periodical: You must specify the start time and duration of data relocation for the storage system to perform data relocation automatically at the specified time. This reduces the management cost and complexity. The data relocation process is transparent to application servers. Automatic data relocation is performed only at the specified time.	[Default value] Manual

      • The SmartTier policy is applicable only when Usage of a storage pool is configured as Block Storage Service.
      • The SmartTier feature requires a license.
      • If Data Migration Plan is set to Periodical, I/Os are monitored on a 7 x 24 basis by default. If Data Migration Plan is set to Manual, you can manually start data migration on the SmartTier page at any time.
      • A storage pool configured with SmartTier needs to reserve free space because SmartTier requires extra data exchange space to dynamically migrate data.
      • For details about SmartTier, refer to the SmartTier feature guide specific to your product model.
   2. Click OK.

      The Create Storage Pool dialog box is displayed.

5. Optional: If there are multiple storage tiers, click Advanced to set the stripe depth.

   Click Advanced. The Advanced Settings dialog box is displayed.

   Table 13-6 Advanced settings parameters

   Parameter	Description	Setting
   Strip Depth	Strip refers to continuous data that is divided into data blocks of the same size and data blocks are distributed on different disks of storage devices. In this way, I/O loads are balanced among disks, improving read/write performance. Strip depth refers to strip size, indicating the size of data blocks on each disk. Smaller strip size indicates smaller data blocks. These data blocks are distributed on more disks, improving transmission performance. However, more time is required to find different data blocks, decreasing disk locating performance. On the contrary, fewer data blocks indicate lower transmission performance but higher disk locating performance. The value of this parameter can be: System auto select The system selects the optimal strip depth based on the RAID policy of the storage tier and data migration granularity. 32 KB 64 KB 128 KB 128 KB is recommended for random read/write services (such as in database scenarios). 256 KB 512 KB 512 KB is recommended for sequential read/write services (such as media asset scenarios) NOTE: The parameter value cannot be changed after being determined.	[Default value] System auto select

6. Confirm the capacity modification of the storage pool.
   1. Click OK.

      If a security alert dialog box is displayed, confirm the information in the dialog box and select I have read and understand the consequences associated with performing this operation. Click OK.

      The Execution Result dialog box is displayed indicating that the operation succeeded.

   2. Click Close.