Add Persistent Volumes

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Introduction

By default, a drive in an edge application is non-persistent. When you run a Purge & Update operation on an application, EVE-OS (Edge Virtualization Engine) wipes any non-persistent drive and rebuilds it from the original source image. All runtime data stored on that drive is permanently deleted. A persistent drive keeps its data through Purge & Update operations, application restarts, and even application deletion. The volume associated with a persistent drive belongs to the node rather than to the application instance, so it has an independent lifecycle. If you want persistent storage available on multiple nodes, you must configure persistence on each application instance separately. Persistence is not a setting on the volume itself. It is a setting on the drive within the edge application definition. You configure it in the Marketplace when you create or edit the edge application.

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Prerequisites

• You have the SysManager or SysAdmin role in your enterprise. See Manage Roles.
• At least one node onboarded to Edge Infrastructure Services.

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Configure a Persistent Drive in the Edge Application

Persistence is set per drive in step 3 (Drives) of the edge application creation or edit wizard in the Marketplace. Each drive card has three toggle controls: Encryption, Persistent, and Purge on Update. To make a drive persistent:

1. In the sidebar, navigate to Marketplace > My Library.
2. Create a new edge application or open an existing one for editing. See Create and Manage an App Image for instructions.
3. In the wizard, advance to the Drives step (step 3).
4. Locate the drive you want to make persistent.
5. Click the Persistent toggle to enable it.

When you enable the Persistent toggle, two things happen automatically:

• The drive’s subtitle changes to Survives app removal, confirming that the volume will not be deleted when the application instance is removed.
• The Purge on Update toggle is disabled and locked. Its subtitle changes to Locked — persistent, because persistent drives are always preserved during purge operations. You do not need to configure Purge on Update separately.

6. Complete the remaining wizard steps and save the edge application definition.

When the application is deployed to a node, EVE-OS creates and manages the volume for this drive automatically on the target node.

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Understand the Purge on Update Toggle

The Purge on Update toggle controls what happens to a non-persistent drive when a Purge & Update is triggered:

• Purge on Update enabled: The drive is wiped and rebuilt from the original source image. All data is permanently deleted.
• Purge on Update disabled: The drive data is preserved during Purge & Update, but the volume is still deleted if the application instance is removed.

For a drive that needs to survive application removal entirely, use the Persistent toggle, not Purge on Update.

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Reset the Contents of a Persistent Volume

Persistent drives do not participate in the standard Purge & Update workflow. If you need to reset the contents of a persistent volume, you must do so manually inside the node or the application.

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Next Steps