NetApp

ONTAP Disk Augment and Aggregate Add-Disks Runbook

Published May 25, 2026 | 9 min read

Scope

This runbook covers adding disks to an existing ONTAP aggregate. NetApp documents storage aggregate add-disks and recommends validating supported drives and platform requirements before adding capacity: storage aggregate add-disks and Add drives to an ONTAP node or shelf.

Prechecks

system health status show
storage aggregate show
storage aggregate show-status -aggregate aggr_data_01
storage disk show -container-type spare
storage disk show -fields owner,container-type,type,usable-size

Confirm:

Check	Requirement
Disk support	Supported by platform and ONTAP release
Disk ownership	Spares owned by the correct node
RAID design	RAID group placement understood
Capacity need	Volume or aggregate growth requirement approved
Firmware/DQP	Reviewed where required by platform process

CLI Process

Simulate first:

storage aggregate add-disks \
  -aggregate aggr_data_01 \
  -diskcount 4 \
  -simulate true

If the simulation result matches the intended disks and RAID group layout, add disks:

storage aggregate add-disks \
  -aggregate aggr_data_01 \
  -diskcount 4

Validate:

storage aggregate show -aggregate aggr_data_01
storage aggregate show-status -aggregate aggr_data_01
storage disk show -aggregate aggr_data_01

REST API Process

Discover aggregate and disks:

curl -k -u admin:'<password>' \
  "https://cluster.example.com/api/storage/aggregates?name=aggr_data_01&fields=uuid,name,node,space,block_storage"

curl -k -u admin:'<password>' \
  "https://cluster.example.com/api/storage/disks?fields=name,state,owner,usable_size,container_type,type"

If your ONTAP release exposes native aggregate disk-add operations through REST, use the documented endpoint only after lab validation. Otherwise, perform the add-disks operation with CLI and use REST for standardized evidence capture.

Post-change REST evidence:

curl -k -u admin:'<password>' \
  "https://cluster.example.com/api/storage/aggregates/<aggregate_uuid>?fields=name,space,block_storage,state"

Best Practices

Use simulation before adding disks.
Prefer ONTAP disk selection unless you have a documented reason to specify disk names.
Avoid mixing disk types, RPMs, or carriers unless the design explicitly allows it.
Keep enough spares after the change.
Record before and after aggregate usable capacity.

Backout

Adding disks is not normally an undo-friendly operation. If the wrong capacity plan was used, stop and open a correction plan rather than trying to manually unwind RAID layout.