Hi Rene, sorry havn't replied sooner.
So what I think you are seeing is that the snapshots have "spilled" over into the volume space used by the data i.e. the remaining 95%.
Your volume was set with a 5% snap reserve, its purpose is a dedicated space to hold all the snapshot copies. However, if the size of the snapshots exceeds that 5% reserve then they will start to consume the remaining space available in the volume, thereby actually reducing the space available to the data. The 5% snapshot reserve is too small to hold all the snapshots, however, neither the volume nor the snapshot reserve size will change.
Hopefully this can explain it for you: Example of what happens when Snapshot copies exceed the reserve - https://library.netapp.com/ecmdocs/ECMP1196991/html/GUID-4547DD0A-4A55-4982-89A0-90AD8A1C86F4.html
Therefore your 868.6% refers to the snapshots consuming more than 8x the space allocated in the snapshot reserve. The SnapVaults will not fail until there is no more space left in the volume. If you were to increase the snapshot reserve to c.60% you should get back to a managable figure. However, this will mean that the data now only has 40% of the volume size available, you may need to resize the volume to account for growth/retention etc.
Regarding the many snapshots you have in the volume, this is most likely to be due to the retention you have set on the SnapVault relaitonship, e.g. to hold 30 days of nightly backups you will have 30 snapshots - one for each night, allowing you to recover to any night over the last 30 days. Once the 30 days have elapsed, during the next SnapVault update the oldest snapshot will expire and so keeping the 30 days retention.This is seperate from the volume scheduled snapshots that you have disabled.
Finally, the backup data as at the last SnapVault update will be in held the volume (as read only) with only the SnapVault snapshots in the .snapshot folder available for point in time restores.
Hopefully this makes sence for you.