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. This is especially true if you are reverting to a release earlier than the immediately previous Data ONTAP release family.

For example, if you are reverting to a release in the 6.4 family from Data ONTAP 7.0, you must review and resolve reversion issues associated with the 6.4 and 6.5 release families (but not 6.3 or earlier) before reverting from 7.0.

For more information, see Appendix C, Understanding Release Family Upgrades.

The following sections discuss revert issues associated with release families:

If you need to revert to a previous release of Data ONTAP, call technical support for assistance. For more information, see Reverting to a previous release.

General guidelines for reverting from Data ONTAP 7.1

The following guidelines apply when reverting from Data ONTAP 7.1 to an earlier version:

You must disable any 7.1 features before reverting.
You cannot revert to a release earlier than Data ONTAP 6.5.
To revert the storage system to an earlier release of Data ONTAP, you must first revert to a Data ONTAP 6.5 family release and once on that release revert to an earlier version.
You cannot revert if an upgrade is in progress.
If you are reverting Data ONTAP on storage systems that are running the SnapMirror software, you must revert the storage systems that have SnapMirror source volumes before you revert the storage systems that have SnapMirror destination volumes.
This requirement applies to both asynchronous and synchronous SnapMirror for volume replication. It does not apply to SnapMirror for qtree replication.

Note
Before reverting the source storage system, you must also disable any features not supported in the earlier release. This means that after reverting, you will no longer be able to mirror certain volumes or their contents to the destination storage system, even if the destination storage system supports that feature.

For example, you must disable FlexVol volumes, as described in FlexVol volumes and data cannot be reverted, before reverting a SnapMirror source system to a release earlier than Data ONTAP 7.0. Although mirrored FlexVol volumes continue to exist on the destination system after the source system has been reverted, you cannot resynchronize the mirrored FlexVol volume on the destination system.

For more information, see Planning for upgrading storage systems running SnapMirror.

Upgrade must complete before any reversion is attempted

If you begin the upgrade procedure to Data ONTAP 7.1 and then decide that you want to revert to an earlier Data ONTAP release, you must complete the 7.1 upgrade before reverting.