Recommendations when migrating FSA Archives from NetApp 7-Mode to C-Mode Volumes.

Problem

Customers who are preparing to migrate their NetApp 7-Mode filers and/or vfilers to C-Mode vservers are being advised to use NetApp 7 Mode Transition Tool (7MTT).
In order to migrate FSA Archives it is imperative to use FSAUtility -pm to correctly update all the database references associated with the migrated placeholders and Archive Points.
 
If only 7MTT is used on its own, the placeholders will be copied to the destination C-Mode volume, however, the full functionality will be broken as the placeholders would not be associated with the records in the database, which still point to the source location.
 
As 7MTT uses SnapMirror, the FSAUtility -pm migration cannot be performed as an initial stage migration step, which would populate the destination volume with content before the copy operation is performed.

Solution

1. FSA Archive Points hosted on 7-Mode Volumes need to be migrated to a temporary Volume, either on 7-Mode or C-Mode, other than the destination Volume.
2. After the Archive Points have been migrated out of the source volumes, 7MTT can be used to migrate the active content to the destination volume on C-Mode.
3. The final stage is to migrate the Archive Points that are hosted on the temporary Volume to the destination Volume on C-Mode.

The Utilities Guide installed with the product documentation provides detailed information on how to use FSAUtility -pm. While environmental factors can affect the processing performed during the migration, if any errors occur the migration will not be completed. It is important to examine the report log corresponding to the FSAUtility execution and identify any issues that may require attention.

If for some reasons the placeholders cannot be created at destination, the –i switch can be added to the syntax to ignore errors. This will allow the migration to complete having all the database records updated to reflect the destination path, but some Placeholders will not be created at destination. The Directory database is used to keep track of failed migrations, therefore it is important to re-execute the same syntax allowing previously failed migrations to be completed.

In the event –i is used, in order to recreate the destination placeholders that were not created during the migration, use FSAUtility –c against the destination path.

After every migration is completed successfully, in order to re-associate the migrated Archive Points with the destination Volume target, the Archiving Task assigned to the destination Volume needs to be launched. It is recommendable to create a dedicated Archiving Task to process the destination Volume target hosting the migrated Archive Points if the existing Task may already be associated with other targets. This provides more granular control over the processing of a single Volume.

Concluding, with the 3 step migration approach, once Archive Points have been migrated to the temporary Volume, the Task associated with the temporary Volume target needs to be executed before performing the final migration to the C-Mode destination Volume.

It is very important to become familiar with the process of migrating placeholders and Archive Points with FSAUtility –pm. The documentation should be studied and a trial run using test resources is highly recommended, before migrating production data.

Additional to the  product documentation that is installed with Enterprise Vault, the articles shown in the Related Articles section provide additional considerations when migrating and consolidating file servers.

7MTT Note:  Please review the following article from the NetApp documentation "7-Mode Transition Tool 2.0 Data and Configuration Transition Guide".

This document describes the different migration processes and phases on page 31 and provides guidelines for deciding when to perform storage cutover on page 118.

We recommend to perform the first step of the migration with FSAUtility –pm at the beginning of Storage Cutover phase, after clients have been disconnected, to help minimize the disruption to clients.

It is important to avoid having any FSA content at the destination as this could interfere with the migration using FSAUtility –pm. Assuming the final data transfer during Storage Cutover will remove all the placeholders and Archive Points from the destination Volume that were copied during the Baseline data copy, then the SnapMirror relationship can be broken, the clients reconnected and the data access validated. At this stage the final step with FSAUtility –pm can be completed to migrate the placeholders and Archive Points from temporary storage to the destination C-Mode Volume.