Network and Storage Protocols

Snaphots and data on volume taking more space than orginally assigned.



We have a cifs flex volume of 200 GB, snapshots are set to 20 % so :

Data can take 160 GB

SnapShots can take 40 GB

We end up with this situation :

Data are taking 140 GB of 160 ( which normal )

SnapShots are taking 130 GB of 40 GB ( which is NOT normal )

When creating the volume, we have reserved 200 GB in total for the data and snapshots. Now, we end up with a situation that space occupied by the data and the snapshots is 270 GB ???

Is it a predictable situation ? When the volume is full, the data is taken from space left in the aggragate ??

Is it possible when we reserve 40 GB for the snapshots that we don't allow the snapshots to take more space ? Same the volume space ?

Thank you,




You cannot stop snapshot'ed data from moving into user space, but you can set up a snap autodelete policy to delete older snapshots when the space fills up. But you may need to figure out what is causing your snapshots to take up more space than you think. Either there is activity that is happening that is not planned (like a massive over-write or a mass delete), or your assumptions about how much space you need based on your retention and schedule need to be revisited.


Hi Adam,

Thank you for the explanation..

I think I am going to activate the snapshots autodelete.

Concerning the users data, are they going to fill up the space which was reserved for the volume like the snapshots or not ?



Hi Dominique,

You may want to have a read through TR-3483 ( Although this TR is focused on best practices around LUNs, it does provide a very good explanation around the various space management features included in ONTAP.

Cheers, Tony


Deal All,

Thank you very much for your answers.