> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cognigy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Migration Guide for Network File Systems

This migration guide helps you migrate to the current NFS structure in on-premises installations.

Several Cognigy.AI features rely on file shares, Network File System (NFS), to store files that multiple services access.

A new NFS structure has been introduced to clearly and consistently reflect [Cognigy.AI's architecture](/ai/administer/installation/architecture). As of Cognigy.AI 4.90.0, the legacy NFS structure, for example, paths using `flow-modules` and `functions` as described in this guide, is deprecated. Migrate to the current NFS structure.

To check if you still use the old NFS structure, search for `flow-modules` and `functions` in your Helm chart file. If you find them, you need to migrate to the current NFS structure.

## Prerequisites

* Cognigy.AI 4.90 or later.
* The `kubectl` utility is installed locally on a Linux or MacOS client host. Windows client hosts aren't supported.
* Helm v3.9 or later installed on the client host.
* Kubernetes cluster meets general Cognigy.AI prerequisites, including hardware resources.
* Runtime and IDE file shares have been deployed.

## Migration Process

To migrate to the current NFS structure, you need to:

1. Adjust feature flags to [handle multiple NFS shares](#activate-the-nfs-restructuring-feature) during the migration process from the old to the current NFS structure.
2. Run the [migration job](#finish-migration-and-switch-to-new-nfs-shares) to copy the data from the old NFS structure into the current NFS structure.
3. [Clean up](#post-migration-steps) the old NFS structure.

While running the migration job, there is no downtime.

## Migration Steps

For this migration guide, consider the namespace as `cognigy-ai` and the Helm chart file name as `cognigy-ai-values.yaml`. You need to adjust the following instructions to match your namespace and Helm chart file name.

### Activate the NFS Restructuring Feature

1. In the `cognigy-ai-values.yaml` file, add the following sections at the root level:

   ```yaml theme={null}
   jobCopyNfs:
       # This will start the migration job automatically with the default configuration
       enabled: true

   migrateFS:
       # This will let the services use the new NFS shares at the same time as the old NFS shares
       enabled: true
       # This flag should be set to true after the migration finishes to use only the new NFS volumes
       finished: false
   ```

2. Deploy the Cognigy.AI Helm chart:

   ```bash theme={null}
   helm registry login cognigy.azurecr.io \
       --username <your-username> \
       --password <your-password>

   helm upgrade --install --namespace cognigy-ai cognigy-ai oci://cognigy.azurecr.io/helm/cognigy.ai --version <Min supported version> --values cognigy-ai-values.yaml
   ```

The pods start running. When the migration job successfully finishes, check the logs to ensure the migration job didn't fail to copy any resources.

### Finish Migration and Switch to New NFS Shares

After the migration job is completed and all resources are located in the new NFS shares, follow these steps:

1. Update the `cognigy-ai-values.yaml` file:

   ```yaml theme={null}
   migrateFS:
       enabled: true
       # Set this flag to true to use only the new NFS volumes
       finished: true

   JobCopyNfs:
       # Set this flag to false to disable the migration job
       enabled: false
   ```

2. Deploy the Cognigy.AI Helm chart:

   ```bash theme={null}
   helm registry login cognigy.azurecr.io \
       --username <your-username> \
       --password <your-password>

   helm upgrade --install --namespace cognigy-ai cognigy-ai oci://cognigy.azurecr.io/helm/cognigy.ai --version <Min supported version> --values cognigy-ai-values.yaml
   ```

The pods start running. Now, the services use only the new NFS.

### Post-Migration Steps

Set `migrateFS.finished` to `true` within seven days after the migration. This setting ensures the migration process is fully completed and stable before finalizing, and automatically deletes the `storageClass` object in the Persistent Volume Claim of the old NFS shares. To clean up these NFS shares completely, proceed as follows:

1. In `cognigy-ai-values.yaml`, remove the trace of `flow-modules` and `functions` by deleting the following code:

   ```yaml theme={null}
   ## aws
   flowModules:
       persistence:
           aws:
               efs:
                   enabled: true
                   id: "fs-xx"
                   efs_csi:
                       enabled: true
   functions:
       persistence:
           aws:
               efs:
                   enabled: true
                   id: "fs-yy"
                   efs_csi:
                       enabled: true
   ## azure
   flowModules:
       persistence:
           storageClass: "flow-modules"
   functions:
       persistence:
           storageClass: "functions"

   .......
       flowmodules:
           enabled: true
           skuName: Premium_LRS
           lfs: false
       functions:
           enabled: true
           skuName: Premium_LRS
           lfs: false
   ```

2. Delete all released volumes that were related to `flow-modules` and `functions`.

## More Information

* [Architecture](/ai/administer/installation/architecture)