Dell PowerVault MD 32XX/36XX Series Storage Arrays CLI Guide

Description

This command reduces the capacity of the disk pool by logically removing the physical disks from the pool. This command uses the Dynamic Capacity Reduction (DCR) feature, which enables you to remove selected physical disks from a disk pool and re-use the removed physical disks as needed.

The maximum number of physical disks that you can remove from a disk pool in a single DCR operation is 12. You cannot reduce the disk pool to below the minimum disk pool size.

Syntax

set diskPool [diskPoolName] 
                                 removeDrives=(enclosureID1,drawerID1,slotID1 
                                 ... enclosureIDn,drawerIDn,slotIDn) 
                              

Parameters

diskPool

removeDrives

Notes

Each disk pool name must be unique. You can use any combination of alphanumeric characters, underscore (_), hyphen(-), and pound (#) for the user label. User labels can have a maximum of 30 characters.

You might want to remove selected physical disks from a disk pool if you need to create a separate group or remove unneeded capacity from the storage array. The removed physical disks become unassigned physical disks and the data that existed on them is redistributed across the remaining physical disks in the disk pool. The capacity of the disk pool is decreased by the capacity of the physical disks that you remove. Removing physical disks from a disk pool is always carried out as a background task and the virtual disks remain fully accessible during this operation. The progress of the removal operation is reported as part of the long running operations status.

This command fails if there is not enough free capacity on the physical disks that remain in the disk pool to store the data that was on the physical disks you remove from the disk pool. Reserve capacity in the disk pool might be used to store data that was on the physical disks you remove from the disk pool. However, if the reserve capacity falls below the critical threshold, a critical event is written to the major event log.

The RAID controller module firmware determines how many physical disks you can remove. You can then select the specific physical disks to be removed. The RAID controller module firmware bases the count on the amount of free space needed to redistribute the data across the remaining physical disks without consuming any capacity reserved for reconstructions. If the free capacity of the disk pool is already less than the Reserved Reconstruction Physical Disk Amount, the RAID controller module does not allow a DCR operation to begin.

A DCR operation might result in the configured capacity exceeding one or both of the Pool Utilization Thresholds. If so, normal threshold alerts are issued.