Administrator Guide

Table 17. Disk group expansion
Disk Group Type Expand Available Notes
Linear Yes Excludes NRAD and RAID 1.
Virtual No Add a new disk group to a virtual pool.
ADAPT Virtual or Linear Yes
When expanding a disk group, all disks in the disk group must be the same type (enterprise SAS, for example). Disk groups
support a mix of 512n and 512e disks. However, for best performance, all disks should use the same sector format. For more
information about disk groups, see About disk groups.
Before expanding non-ADAPT disk groups, back up the data for the disk group so that if you need to stop expansion and delete
the disk group, you can move the data into a new, larger disk group.
NOTE: Expansion can take hours or days to complete, depending on the RAID level and size of the disk group, disk speed,
utility priority, and other processes running on the storage system. You can stop expansion only by deleting the disk group.
For ADAPT disk groups, expansion is very fast and extra capacity is immediately available when rebalancing is not needed. If
rebalancing is needed, extra capacity may not be available until rebalancing is complete.
When disks are added to an ADAPT disk group, the system will first replenish any spare capacity needed to be fully fault-
tolerant, then use the remainder for expansion of user data capacity. When set to the default spare capacity, the system will try
to replenish spare capacity to be the sum of the largest two disks in the group.
●
When default spare capacity has been overridden the system will try to replenish spare capacity to meet the configured
target GiB. For more information, see the topic about the add disk-group command in the Dell EMC PowerVault ME4
Series Storage System CLI Guide.
● If the actual spare capacity meets the target spare capacity, the new disk capacity will be allocated to user data. For
information on how ADAPT disk groups manage sparing, see About RAID levels.
There are three sections that comprise the Expand Disk Group panel. The top section displays information about the disk group,
including its name, type, owner (controller), and data protection (RAID) level. The information that is based on the type of disk
group being expanded.
The middle section contains the disk selection sets summary and Disks table which presents cumulative data for existing disks
and dedicated spares in the disk group as well as for selected disks. The amount of disk space is color-coded to show total,
available, dedicated spares, and overhead disk space amounts.
The Disks table lists information about the disks and dedicated spares in the disk group, updating as you select disks to expand
the disk group to show the total number of disks selected and the total size of the disk group.
The bottom section lists the disks in each enclosure in your system, along with their details. Select the disks that you want to
add to the current disk group by doing one of the following:
● Select a range of disks within an enclosure by entering a comma-separated list that contains the enclosure number and
disk range in the Enter Range of Disks text box. Use the format enclosure-number.disk-range,enclosure-
number.disk-range. For example, to select disks 3-12 in enclosure 1 and 5-23 in enclosure 2, enter 1.3-12,2.5-23.
● Select all disks by checking the Select All checkbox.
● Filter the disks in the list per disk description, enclosure ID, slot location, or disk size by entering applicable search criteria in
the text box. Clear the filter by clicking the Clear Filters button.
● Click on individual disks within the table to select them and add them to the disk group.
Selected disks are highlighted in blue. To remove disks from the group, click on them the disks to deselect them.
Expand a disk group
1. In the Pools topic, select the pool for the disk group that you are expanding. Then select the disk group in the Expand Disk
Group table.
NOTE:
To see more information about a pool, hover the cursor over the pool in the table. Viewing pools contains more
details about the Pool Information panel that appears.
2. Select Action > Expand Disk Group. The Expand Disk Group panel opens displaying disk group information and disk tables.
3. For disk groups with RAID-10 or RAID-50 configurations, choose the number of new sub-groups in the Additional Sub-groups
list.
4. Select additional disks that you want to add to the disk group from the table in the bottom section.
Working in the Pools topic
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