3.5.6 Expansion of Capacity of Sub-Pool

It is possible to expand the capacity of the sub-pools which configure a Tier pool.
The items which can be specified in sub-pool capacity expansion are as follows.

Basic Configuration Items of Tier Pool

Item	Specification	Explanation
Assigned CM	Optional	Only for the Tier pool that the CM in charge has been specified, a CM in charge can be added. The checkbox is not checked by default (a CM in charge is not added). To add a CM which takes charge of the Tier pool, check off the checkbox.
Disk Selection	Optional	Specify the method for the selection of disks that configure the sub-pool. The default setting is "Auto" (automatic selection). When "Auto" is selected, in the screen to configure the sub-pool, it is necessary to specify a minimum required capacity for the sub-pool. When "Manual" is selected, in the screen to configure the sub-pool, it is necessary to specify the disks that configure the sub-pool.

Item

Specification

Explanation

Assigned CM

Optional

Only for the Tier pool that the CM in charge has been specified, a CM in charge can be added.

The checkbox is not checked by default (a CM in charge is not added).

To add a CM which takes charge of the Tier pool, check off the checkbox.

Disk Selection

Optional

Specify the method for the selection of disks that configure the sub-pool.
The default setting is "Auto" (automatic selection).

When "Auto" is selected, in the screen to configure the sub-pool, it is necessary to specify a minimum required capacity for the sub-pool.

When "Manual" is selected, in the screen to configure the sub-pool, it is necessary to specify the disks that configure the sub-pool.

Configuration Items of Sub-Pool

If "Auto" is selected for Disk Selection of "Basic Configuration Items of Tier Pool":

Item	Specification (*1)	Explanation
FTSP Name	Required	Specify a name for the sub-pool that the capacity is being expanded. In the default setting, the name of the target sub-pool is displayed. However, its name can be changed. When change the name, specify a name that is unique within the storage device. Any alphanumeric character (1 - 16 characters), a hyphen (-), an underscore (_), and a pound symbol (#) may be specified. The letters to be specified are not case sensitive.
Balancing	Optional	Specify the implementation of Tier pool balancing. The checkbox is not checked by default (Tier pool balancing is not implemented). Check the checkbox when starting the Tier pool balancing simultaneously with the sub-pool capacity expansion.
Minimum Required Capacity	Required	Specify the minimum capacity required for the sub-pool. A capacity of 1 MB or more may be specified. It is also possible to enter a decimal value. A drive is automatically selected in accordance with the specification of the existing RAID group and a sub-pool is extended to a capacity greater than or equal to the specified capacity. If the firmware version of the storage device is V10L70 or late The maximum capacity that can be extended for the sub-pool is displayed in the format "(MAX: maximumCapacityToBeExtended)". For example, the maximum capacity that can be extended for the sub-pool is up to 1 PB, this is displayed as "(MAX: 1PB)". Specify a value less than or equal to the displayed capacity for this item.
Specify Assigned CM	Optional	As needed, specify the CM which takes charge of the RAID group configuring the sub-pool. The checkbox is not checked by default (a CM in charge is not specified). Any CM in charge can be configured from the CM in charge specified to the Tier pool. To specify a CM in charge, check the checkbox.

*1: When a specification is omitted for the item of which specification is "Optional", a default value is configured.

If "Manual" is selected for Disk Selection of "Basic Configuration Items of Tier Pool":

Item	Specification (*1)	Explanation
FTSP Name	Required	Specify a name for the sub-pool that the capacity is being expanded. In the default setting, the name of the target sub-pool is displayed. However, its name can be changed. When change the name, specify a name that is unique within the storage device. Any alphanumeric character (1 - 16 characters), a hyphen (-), an underscore (_), and a pound symbol (#) may be specified. The letters to be specified are not case sensitive.
Balancing	Optional	Specify the implementation of Tier pool balancing. The checkbox is not checked by default (Tier pool balancing is not implemented). Check the checkbox when starting the Tier pool balancing simultaneously with the sub-pool capacity expansion.
Disk	Required	Specify the disk of the RAID group that configures the sub-pool. The number of disks required differs depending on the reliability of the RAID group.
Specify Assigned CM	Optional	As needed, specify the CM which takes charge of the RAID group configuring the sub-pool. The checkbox is not checked by default (a CM in charge is not specified). Any CM in charge can be configured from the CM in charge specified to the Tier pool. To specify a CM in charge, check the checkbox.

*1: When a specification is omitted for the item of which specification is "Optional", a default value is configured.

Refer to "Expand Capacity of Sub Pool in Tier Pool" in the Web Console Guide for information on how to expand the capacity of a sub-pool.

Note

If a sub-pool capacity expansion is performed, data bias occurs in the sub-pool, and differences may appear in access performance. To eliminate the data bias, perform a Tier pool balancing.
A Tier pool balancing can be carried out after extending the sub-pool capacity as well as when extending sub-pool capacity. Refer to the "Start/Stop Tier Pool Balancing" in the Web Console Guide for information on how to perform a Tier pool balancing.

See

Refer to "4.8 Tier Pool Balancing" for details about the Tier pool balancing.

Point

For the Tier pool in which RAID groups are being deleted, a sub-pool capacity expansion cannot be performed.