Reversion issues between release families

Why there might be issues

You might encounter issues if you upgrade and then decide to revert to a previous version of Data ONTAP, because features introduced in a new release might be incompatible with features of the previous release.

If you need to revert to a previous release of Data ONTAP, call Network Appliance Technical Support for assistance. For more information, see Reverting to a previous release.

General guidelines for reverting from Data ONTAP 6.4

The following guidelines apply when reverting from Data ONTAP 6.4 to an earlier version:

You must disable any 6.4 features before reverting.
You cannot revert directly to a release earlier than Data ONTAP 6.2.
To revert the filer to an earlier release of Data ONTAP, you must first revert to a Data ONTAP 6.2.x release and once on that release revert to an earlier version.
You cannot revert if an upgrade is in progress.

Upgrade must complete before any reversion is attempted

If you begin the upgrade procedure to Data ONTAP 6.4 and then decide that you want to revert to an earlier Data ONTAP release, you must complete the 6.4 upgrade before reverting.

Stale file handles on vFilers

Data ONTAP 6.4 included a change in the Network File System (NFS) file handle format that is not backward compatible with vFiler^TM systems. If you have defined vFiler storage on your system, and you upgrade to 6.4 or later and then revert to an earlier version, NFS clients might report stale file handles on the vFilers. To prevent this problem, unmount any NFS clients that are mounted on vFilers. You can remount them after reverting.

Finding reversion issues for releases earlier than Data ONTAP 6.3

To find reversion issue information for releases earlier than Data ONTAP 6.3, go to the Information Library for Archived Documentation on the NOW site, at http://now.netapp.com/NOW/knowledge/docs/archive_docs.shtml, for a list of documentation for earlier releases of Data ONTAP.

Reversion with home directory paths in the cifs_homedir.cfg file

If you upgrade to Data ONTAP 6.3 or later and convert home directory path entries from the cifs.home_dir option to the cifs_homedir.cfg file, then if you revert to a pre-6.3 release, the filer will attempt to write as many of the paths as possible back to the registry for the cifs.home_dir option. If some of the paths fail to be written to the registry, you might need to manually transfer the paths from the cifs_homedir.cfg file to the cifs.home_dir option. The cifs_homedir.cfg file remains intact during reversion.