Administrator Guide

Table 16. Disk group options (continued)
Option Description
RAID Level Select one of the following RAID levels when creating a virtual or linear disk group:
• RAID 1 – Requires 2 disks.
• RAID 5 – Requires 3-16 disks.
• RAID 6 – Requires 4-16 disks.
• RAID 10 – Requires 4-16 disks, with a minimum of two RAID-1 subgroups, each having
two disks.
• RAID 50 – (only appears for linear disk groups). Requires 6-32 disks, with a minimum
of two RAID-5 subgroups, each having three disks.
• ADAPT – Requires 12-128 disks.
To create an NRAID, RAID-0, or RAID-3 (linear-only) disk group, you must use the CLI
add disk-group command. For more information on this command, see the Dell
EMC PowerVault ME4 Series Storage System CLI Guide.
Number of Sub-groups (options only appear
when RAID-10 or RAID-50 is selected)
Changes the number of sub-groups that the disk group should contain.
Chunk size (optional, only for linear non-
ADAPT disk groups)
Specifies the amount of contiguous data, in KB, that is written to a group member before
moving to the next member of the group. For NRAID and RAID 1, chunk-size has no
meaning and is therefore not applicable. For RAID 50, this option sets the chunk size of
each RAID-5 subgroup. The following chunk size options are available when creating a
linear disk group:
• 64k
• 128k
• 256k
• 512k
For a virtual group, the system uses one of the following chunk sizes, which cannot be
changed:
○ RAID 1: Not applicable
○ RAID 5 and RAID 6:
▪ With 2, 4, or 8 non-parity disks: 512k. For example, a RAID-5 group with 3, 5,
or 9 total disks or a RAID-6 group with 4, 6, or 10 total disks.
▪ Other configurations: 64k
○ RAID 10: 512k
Online Initialization (only appears for linear
disk groups)
Specifies whether the group is initialized online or offline.
• Online. When the Online Initialization check box is selected, you can use the group
immediately after creating it while it is initializing. Because online uses the verify
method to create the group, it takes longer to complete initializing than offline. Online
initialization is fault-tolerant.
• Offline. When the Online Initialization check box is cleared, you must wait for the
group initialization process to finish before using the group. However, offline takes less
time to complete initializing than online.
Add a disk group
Perform the following steps to add a disk group:
1. In the Pools topic, select Action > Add Disk Group. The Add Disk Group panel opens.
2. Set the options. See Disk group options for more information.
3. If you are creating a linear disk group, select the RAID number or SPARE option to determine if you are selecting disks for the RAID
configuration or as dedicated spares for the disk group.
NOTE: The ADAPT RAID level does not have a dedicated spare option.
4. Select the disks that you want to add to the disk group from the table.
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Working in the Pools topic