Adding new disks in the declustered array of the recovery group
This topic describes the procedure for adding new disks in declustered array of recovery group. The newly added disks must meet the IBM Storage Scale Erasure Code Edition hardware requirements and considerations.
For more information, see Planning for recovery group space and scale up.
Use the following steps to add new disks in the declustered array of the recovery group.
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Verify the current disk topology of the server by running the following command:
# mmvdisk server list --nc nc_1 --disk-topology
The system displays the following output:
node needs matching number server attention metric disk topology ------ -------------------------------- --------- -------- ------------- 5 node5.ibm.com no 100/100 ECE 6 SSD/NVMe and 2 HDD 1 node1.ibm.com no 100/100 ECE 6 SSD/NVMe and 2 HDD 2 node2.ibm.com no 100/100 ECE 6 SSD/NVMe and 2 HDD 3 node3.ibm.com no 100/100 ECE 6 SSD/NVMe and 2 HDD 4 node4.ibm.com no 100/100 ECE 6 SSD/NVMe and 2 HDD
- Check the details of the declustered array that needs to be expanded.
In the following example, DA2 is the declustering array (DA) that would be expanded. DA2 currently has 10 disks.
# mmvdisk rg list --da
The system displays the following output:
declustered needs capacity pdisks recovery group array service type trim total raw free raw free% total spare background task -------------- ----------- ------- ---- ---- --------- -------- ----- ----- ----- --------------- rg_1 DA1 no NVMe yes 7095 GiB 725 GiB 10% 10 2 scrub (41%) rg_1 DA2 no HDD no 4414 GiB 459 GiB 10% 10 2 scrub (41%) rg_1 DA3 no SSD no 7866 GiB 796 GiB 10% 20 2 scrub (39%) mmvdisk: Total capacity is the raw space before any vdisk set definitions. mmvdisk: Free capacity is what remains for additional vdisk set definitions.
- Insert new disks into the slots on each server.
# mmvdisk server list --nc nc_1 --disk-topology
The system displays the following output:
node needs matching number server attention metric disk topology ------ -------------------------------- --------- -------- ------------- 5 node5.ibm.com no 100/100 ECE 6 SSD/NVMe and 3 HDD 1 node1.ibm.com no 100/100 ECE 6 SSD/NVMe and 3 HDD 2 node2.ibm.com no 100/100 ECE 6 SSD/NVMe and 3 HDD 3 node3.ibm.com no 100/100 ECE 6 SSD/NVMe and 3 HDD 4 node4.ibm.com no 100/100 ECE 6 SSD/NVMe and 3 HDD
- Verify that the slot location of the newly inserted disks is correct. For more information, see Mapping NVMe disk slot location and Mapping LMR disk location.
- Add new disks in the declustered array by running the following command:
# mmvdisk rg resize --rg rg_1
mmvdisk: Obtaining pdisk information for recovery group 'rg_1'. mmvdisk: Analyzing disk topology for node 'c72f4m5u19-ib0'. mmvdisk: Analyzing disk topology for node 'c72f4m5u13-ib0'. mmvdisk: Analyzing disk topology for node 'c72f4m5u21-ib0'. mmvdisk: Analyzing disk topology for node 'c72f4m5u17-ib0'. mmvdisk: Analyzing disk topology for node 'c72f4m5u11-ib0'. mmvdisk: Validating existing pdisk locations for recovery group 'rg_1'. mmvdisk: The resized server disk topology is 'ECE 6 SSD/NVMe and 3 HDD'. mmvdisk: Validating declustered arrays for recovery group 'rg_1'. mmvdisk: Adding new pdisks to recovery group 'rg_1'. mmvdisk: Updating declustered array attributes for recovery group 'rg_1'. mmvdisk: Successfully resized recovery group 'rg_1'.
- Check the declustered array information.
In this example, DA2 has 15 disks now.
# mmvdisk rg list --da
The system displays the following output:
declustered needs capacity pdisks recovery group array service type trim total raw free raw free% total spare background task -------------- ----------- ------- ---- ---- --------- -------- ----- ----- ----- --------------- rg_1 DA1 no NVMe yes 7095 GiB 725 GiB 10% 10 2 scrub (46%) rg_1 DA2 no HDD no 7174 GiB 3219 GiB 44% 15 2 scrub (46%) rg_1 DA3 no SSD no 7866 GiB 796 GiB 10% 20 2 scrub (45%) mmvdisk: Total capacity is the raw space before any vdisk set definitions. mmvdisk: Free capacity is what remains for additional vdisk set definitions.
- Use mmvdisk command to create vdisks and NSDs as
required.
For more information on the management of the recovery groups, see the topic Recovery group management in the IBM Storage Scale RAID: Administration and Programming Reference Guide.