David I believe you are asking if I modify the database to reference the appropriate filer type will it use the correct API for monitoring and be able to access the already existing shares?
The quick answer is not so complicated since it would not be possible with a single edit, is not supported and I personally would advise against it.
The longer answer is the configuration files, database references and creation of the device does not touch only one location and although you believe the share will be the same to end users you are likely referring to the share name since the UNC, the physical path and the reference will all have to change from the network and infrastructure context. It would be an expensive consulting engagement to complete the task if there was such an offering from Veritas.
Note: UNC assumes namespace cannot exist in two places at once.
The recommended path to follow would be to continue scanning and even monitoring ( I would suggest exclusion of the migration process though as every file object will be touched) the celerra until the new Unity filer is fully in place and under the DI (Data Insight) environment. Then disabling the older celerra filer once the migration is completed and leaving it in place in DI to preserve historical data. By scanning / monitoring both you will have consistent records. Any integration with other products such as Veritas Enterprise Vault or Symantec's Data Loss Prevention will also have to be configured for the new array.
Once the Unity is the current array for the DI perspective with the Celerra is decommissioned and disabled in the DI console you would keep the historical data for the duration of your data retention period so as to allow reporting for a scope that is in the past beyond the existence of the Unity array. Eventually your data will age out and the old array can be deleted from the DI console. Veritas Support can assist you with any of these concepts mentioned or the actual configuration. The Unity prerequisites are listed in the Hardware and Software compatibility guide for the versions supporting it. I recommend version 6.1x. The installation requirements are in the Installation Guide for the product. You can find the guides by selecting the appropriate product, then version from the https://sort.veritas.com/documents page.
I hope that clears things up for you in regards to the question you asked?
Yes this clears up things. I have a followup though. I understand I will need to create a new filer when the share is migrated. What I don't understand how to do though is how to do this with the console. Let me explain what is being done.
We have a filer defined NAS01 with a number of shares. Some of these shares reside on the Unity filer while a couple still reside on the Celerra filer.
Can I add both a Unity filer with the filer name NAS01 at the same time as a Celerra filer exists with the same name? The filer control host is different for both.
David when adding as a filer the creation under celerra it would require the CIFS Server name (Assume this is NAS01) and the control Station hostname or IP. It will be recorded as the CIFS server name. While you cannot have duplicate names there are other combinations that will allow you to enter the Unity array.
In a Unity array you enter the Cluster Management Host of the controller and discover the name of the CifsServer. Any name that was different like a FQDN or a designation would be allowed.
Since you are very likely to not want to change the name to allow for existing roaming profile mounts or known shares to remain the same during / post migration there may be an issue with the two names showing the same in the console that would create a problem in creation as the device name would be taken.
The shares would be designated by the device name / share for the uncpath_prefix but the share name and internal prefix would be identical.
Note: I created a share NAS01 for demonstration only whereas my emccelerra name would correspond to your filer name NAS01.
I would suggest a support case to determine your options for this scenario, otherwise I would expect the failure