NetApp

ONTAP Volume Autosize and Snapshot Autodelete Runbook

Published May 25, 2026 | 10 min read

Why Autosize Needs Guardrails

Volume autosize and snapshot autodelete are useful when a workload can grow unexpectedly, but they can also hide bad retention, runaway writes, or a capacity model that no longer fits. Use them as controlled safety rails, not as a replacement for monitoring.

NetApp documents automatic snapshot deletion with volume snapshot autodelete modify and notes that it can help manage space utilization: Enable automatic ONTAP snapshot and LUN deletion. The command reference also documents volume snapshot autodelete show and modify: volume snapshot autodelete modify.

Lab Example

Volume: autosize_demo_vol01
SVM: svm_nfs01
Starting size: 256MB
Max autosize: 512MB
Autosize mode: grow
Grow threshold: 85%
Snapshot autodelete trigger: snap_reserve
Delete order: oldest_first
Target free space: 20%

CLI Process

Capture current settings:

volume show -vserver svm_nfs01 -volume autosize_demo_vol01 -fields size,autosize-mode,max-autosize,grow-threshold-percent
volume show-space -vserver svm_nfs01 -volume autosize_demo_vol01
volume snapshot autodelete show -vserver svm_nfs01 -volume autosize_demo_vol01
volume snapshot show -vserver svm_nfs01 -volume autosize_demo_vol01

Enable autosize growth:

volume autosize \
  -vserver svm_nfs01 \
  -volume autosize_demo_vol01 \
  -mode grow \
  -maximum-size 512MB \
  -grow-threshold-percent 85

Enable snapshot autodelete:

volume snapshot autodelete modify \
  -vserver svm_nfs01 \
  -volume autosize_demo_vol01 \
  -enabled true \
  -trigger snap_reserve \
  -delete-order oldest_first \
  -target-free-space 20

Validate:

volume autosize -vserver svm_nfs01 -volume autosize_demo_vol01
volume snapshot autodelete show -vserver svm_nfs01 -volume autosize_demo_vol01
volume show-space -vserver svm_nfs01 -volume autosize_demo_vol01

REST API Process

Discover the volume:

curl -k -u admin:'<password>' \
  "https://cluster.example.com/api/storage/volumes?svm.name=svm_nfs01&name=autosize_demo_vol01&fields=uuid,name,space,autosize,snapshot_policy"

Patch autosize settings:

curl -k -u admin:'<password>' \
  -X PATCH \
  "https://cluster.example.com/api/storage/volumes/<volume_uuid>" \
  -H "Content-Type: application/json" \
  -d '{
    "autosize": {
      "mode": "grow",
      "maximum": 536870912,
      "grow_threshold": 85
    }
  }'

Snapshot autodelete REST coverage varies by ONTAP release. If native fields are available in your release, use the storage volume snapshot/autodelete resource from that release's API docs. Otherwise, execute the autodelete change with CLI and capture REST evidence for volume space and snapshot state.

curl -k -u admin:'<password>' \
  "https://cluster.example.com/api/storage/volumes/<volume_uuid>?fields=name,space,autosize"

Best Practices

• Set a maximum size that the aggregate can actually tolerate.
• Alert on autosize events instead of letting them become invisible.
• Use oldest_first only after confirming retention requirements.
• Do not enable autodelete on SnapMirror destination volumes expecting the same behavior as read-write volumes.
• Record the business owner who approved losing older snapshots under pressure.

Backout

volume autosize -vserver svm_nfs01 -volume autosize_demo_vol01 -mode off
volume snapshot autodelete modify -vserver svm_nfs01 -volume autosize_demo_vol01 -enabled false

Validate capacity immediately after disabling either feature.

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