Scaling Storages ​

This guide explains how to use the Expand Volume interface to increase the storage capacity of your database. Two approaches are available — a manual Expand Volume operation for an immediate one-time resize, and Storage Autoscaling which automatically expands storage based on usage thresholds.

1. Getting Started ​

To begin, select Scale Storage from the Operations section in the left sidebar.

You will land on the Expand Volume form, which contains two method cards at the top:

  • Expand Volume — Manually increase the database storage volume to a specified size.
  • Storage Autoscaling — Automatically scale storage capacity based on configurable usage thresholds.

Expand Volume form showing method selection cards, Mode dropdown, Standalone volume expansion, and OpsRequest Options

2. Expand Volume ​

Use this method to perform an immediate, one-time expansion of your database storage to a specific size.

Expand Volume method selected showing Mode dropdown and Standalone current-to-new storage size input

2.1 - Selecting the Mode ​

The Mode dropdown controls how the volume expansion is applied to the database nodes:

  • Online — Expands storage while the database remains operational, with minimal disruption.
  • Offline — The database is briefly stopped during expansion. Use this if your storage provider does not support online resizing.

Tip: Use Online mode wherever possible to avoid downtime. Choose Offline mode only if your storage class does not support live volume expansion.

2.2 - Configuring Standalone Storage ​

The Standalone panel specifies how much storage to allocate:

  1. Current Storage: Displays the current storage size of the database (read-only, shown for reference).

  2. New Standalone: Enter the new target storage size (e.g., 5Gi). The value must be larger than the current size.

  3. Preview: Click Preview to review the generated OpsRequest before applying it.

  4. Submit: Once satisfied, click Submit to apply the storage expansion.

Note: After every Preview, you must click Submit to save your changes.

Tip: On the Preview page, you can also switch to YAML or JSON view to edit the configuration directly before submitting.

3. Storage Autoscaling ​

Use this method to configure automatic storage expansion. The system monitors storage usage and expands capacity automatically when defined thresholds are crossed.

Storage Autoscaling method selected showing Trigger toggle, Expansion Mode, Standalone, Readiness Criteria, Timeout, and Apply sections

3.1 - Trigger ​

Toggle Trigger to enable or disable the autoscaling policy. When enabled, the autoscaler monitors storage usage and acts according to the rules defined below.

3.2 - Expansion Mode (Online/Offline) ​

Choose how the autoscaler expands storage when a threshold is triggered:

  • Online — Expands storage while the database remains operational and serves requests.
  • Offline — Pauses the database during expansion. Suitable for storage classes that do not support live resizing.

3.3 - Standalone Autoscaling Rules ​

The Standalone panel defines the usage threshold and scaling rules for standalone database nodes.

Standalone panel showing UsageThreshold slider, Scaling Rules with Initial Storage and percentage steps, and UpperBound field

FieldDescription
UsageThreshold (%)The storage usage percentage at which autoscaling is triggered. Adjust using the slider or enter a value directly (0–100%).
Scaling Rules — Initial StorageThe starting storage size from which scaling steps are calculated (e.g., 1Gi).
Scaling Rules — StepThe percentage by which storage is increased at each scaling step (e.g., 20% after the threshold is reached for 1Gi storage).
UpperBoundThe maximum storage size the autoscaler is allowed to provision. Expansion stops once this limit is reached.

Use Add New Rule to define additional scaling steps for different storage size ranges.

3.4 - Readiness Criteria ​

The Readiness Criteria panel defines conditions that must be met before the autoscaler considers the database ready to accept a storage expansion.

Readiness Criteria panel showing Objects Count Diff Percentage slider and Oplog Max Lag Seconds field

FieldDescription
Objects Count Diff PercentageThe maximum acceptable difference (%) in object counts between primary and secondaries before expansion is allowed. Adjust using the slider (0–100%).
Oplog Max Lag SecondsThe maximum acceptable oplog replication lag (in seconds) before expansion is allowed (e.g., 10).

Note: These criteria ensure storage is only expanded when the database is in a healthy, consistent state — preventing expansion during replication lag or data inconsistency.

3.5 - Timeout and Apply ​

  1. Timeout: Specify the maximum time allowed for the autoscaling operation to complete. Use formats like 30sec, 1min, or 2h.

  2. Apply: Choose when the OpsRequest should be applied:

    • IfReady — The operation will only be applied if the database is in a ready state. This is the recommended option.
    • Always — The OpsRequest will be applied regardless of the database's current state.

  3. Preview: Click Preview to review the generated autoscaling manifest.

  4. Submit: Once satisfied, click Submit to activate the autoscaling policy.

Quick Reference ​

ActionHow to do it
Manually expand storageSelect Expand Volume → set Mode → enter new size in Standalone → Preview → Submit
Enable storage autoscalingSelect Storage Autoscaling → enable Trigger → set thresholds and rules → Preview → Submit
Set expansion modeMode dropdown → choose Online or Offline
Define scaling rulesStandalone → set UsageThreshold, Scaling Rules, and UpperBound
Set readiness conditionsReadiness Criteria → set Objects Count Diff % and Oplog Max Lag Seconds
Edit manifest before applyingUse the YAML / JSON toggle on the Preview page
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