topic Re: Tool or a way to simulate overwriting of a lun? in ONTAP Discussions https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34916#M8276 <HTML><HEAD></HEAD><BODY><P>You need to take a snapshot.</P><P></P><P>Write the volume full, then snapshot it, then remove and rewrite with fresh data. At this point, if you have set the fractional reservation to 50% and the volume size is thick provisioned at 150% of the LUN size, then you should run out of space! Depending on other factors, such as aggregate free space, will depend on how the LUN reacts to this.</P></BODY></HTML> Thu, 05 Mar 2009 21:08:05 GMT chriskranz 2009-03-05T21:08:05Z Tool or a way to simulate overwriting of a lun? https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34911#M8273 <HTML><HEAD></HEAD><BODY><P>I am trying to grasp fractional reserve adn I am simulating this in my lab with a Windows machine connected to a iSCSI LUN on a Netapp.</P><P></P><P>How do I simulate overwriting a LUN? Because once the file system disk is full in my Windows disk, I cannot overwrite these blocks.</P><P></P><P>what I want to see is if I can overwrite as much as the fractional rserve is set at. My understanding is that if this is set at 50%, I can only overwrite 50% og the original LUN size.</P></BODY></HTML> Thu, 05 Jun 2025 07:30:14 GMT https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34911#M8273 atle 2025-06-05T07:30:14Z Re: Tool or a way to simulate overwriting of a lun? https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34916#M8276 <HTML><HEAD></HEAD><BODY><P>You need to take a snapshot.</P><P></P><P>Write the volume full, then snapshot it, then remove and rewrite with fresh data. At this point, if you have set the fractional reservation to 50% and the volume size is thick provisioned at 150% of the LUN size, then you should run out of space! Depending on other factors, such as aggregate free space, will depend on how the LUN reacts to this.</P></BODY></HTML> Thu, 05 Mar 2009 21:08:05 GMT https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34916#M8276 chriskranz 2009-03-05T21:08:05Z Re: Tool or a way to simulate overwriting of a lun? https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34921#M8279 <HTML><HEAD></HEAD><BODY><P>removed</P></BODY></HTML> Tue, 10 Mar 2009 09:10:43 GMT https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34921#M8279 atle 2009-03-10T09:10:43Z Re: Tool or a way to simulate overwriting of a lun? https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34925#M8282 <HTML><HEAD></HEAD><BODY><P>removed</P></BODY></HTML> Tue, 10 Mar 2009 09:14:00 GMT https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34925#M8282 atle 2009-03-10T09:14:00Z Re: Tool or a way to simulate overwriting of a lun? https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34929#M8284 <HTML><HEAD></HEAD><BODY><P>removed</P></BODY></HTML> Tue, 10 Mar 2009 09:59:25 GMT https://community.netapp.com/t5/ONTAP-Discussions/Tool-or-a-way-to-simulate-overwriting-of-a-lun/m-p/34929#M8284 atle 2009-03-10T09:59:25Z