Creating data reduction pools

To use data reduction on the system, you need to create a data reduction pool, create thin-provisioned or compressed volumes, and map these volumes to hosts that support SCSI unmap commands.

Data reduction can increase storage efficiency and performance and reduce storage costs, especially for flash storage. Data reduction reduces the amount of data that is stored on external storage systems by reclaiming previously used storage resources that are no longer needed by host systems. The system supports data reduction pools, which contain thin-provisioned or compressed volumes as well as specific volumes that track when space is freed from hosts. When space is freed from hosts, the process is called unmapping. Unmap is a set of SCSI commands that hosts use to indicate that allocated capacity is no longer required on a target volume. The freed space can be collected and reused on the system without the reallocation of capacity on the external storage system. When a system uses either compressed or thin-provisioned volumes or a combination of these volume types in data reduction pools, hosts can automatically allocate and unmap storage without intervention. Reclaimed capacity can be used for other volumes, which more efficiently uses existing storage resources. When a data reduction pool is created, the system monitors the pool for reclaimable capacity from host unmap operations. This capacity can be reclaimed by the system and redistributed into the pool. To maximize space within the pool, create volumes that use thin provisioning or compression within the data reduction pool.

Using the management GUI

To create data reduction on the system, complete these steps:
  1. Create a data reduction pool by completing these steps:
    1. In the management GUI, select Pools > Pools.
    2. On the Pools page, click Create.
    3. On the Create Pool page, enter a name of the pool and select Data Reduction.
    4. Click Create.Data reduction pools are created as parent pools only, not child pools.
  2. In the management GUI, select Pools > Actions > Add Storage, and then assign storage to the data reduction pool.
  3. Create compressed or thin-provisioned volumes for the data reduction pool and map them to hosts by completing these steps:
    1. In the management GUI, select Volumes > Volumes.
    2. On the Volumes page, click Create Volumes.
    3. On the Create Volume page, you can create different types of volumes. The type of volumes that you can create depends on the type of topology that is configured on your system. If your system uses standard topology, which is single-site configuration, select one of these types of volumes:
      • Basic
      • Mirrored
      • Custom
      If your system uses HyperSwap topology, which is also multiple-site configuration, select one of these types of volumes:
      • Basic
      • HyperSwap
      • Custom
  4. Select the data reduction pool that you created previously and enter details for the new volume.
  5. Enter the Volume Details for the new volume, such as name and capacity.
  6. Click Create and Map.
    Note: Select Create to create the volumes in the data reduction pool without mapping to hosts. If you want to map volumes to hosts later, select Hosts > Hosts > Add Hosts.
  7. On the Create Mapping page, select Host to display all hosts that are available for mapping. Hosts must support SCSI unmap commands. Verify that the selected host type supports SCSI unmap commands. Click Next.
  8. Verify that volume and click Map Volumes.

Using the command-line interface

To create data reduction on the system, complete these steps:
  1. To create a data reduction pool, enter the following command:
    mkmdiskgrp -pool pool_name -ext extent_size -datareduction yes
    Where pool_name is the name of the pool and extent_size is the extent size of the pool.Data reduction pools are created as parent pools only, not child pools.
  2. To create a compressed or thin-provisioned volume within a data reduction pool, enter the following command:
    mkvolume -name name -pool storage_pool_name -size disk_size -compressed
    mkvolume -name name -pool storage_pool_name -size disk_size -thin
    Where name is the name of the new volume, storage_pool_name is the name of the data reduction pool, and disk_size is the capacity of the volume.
  3. To map the volume to a host, enter the following command:
    mkvdiskhostmap -host host_namevdisk_name
    Where host_name is the name of the host and vdisk_name is the name of the volume.
Parent topic: Managing MDisks and pools