# Creating an iSCSI LUN
<a name="create-iscsi-lun"></a>

This process describes how to create an iSCSI LUN on an Amazon FSx for NetApp ONTAP file system using the NetApp ONTAP CLI **lun create** command. For more information, see [https://docs.netapp.com/us-en/ontap-cli-9111/lun-create.html](https://docs.netapp.com/us-en/ontap-cli-9111/lun-create.html) in the NetApp ONTAP Documentation Center.

**Note**  
The iSCSI protocol isn't supported for file systems with more than six HA pairs.

This process assumes you already have a volume created on your file system. For more information, see [Creating volumes](creating-volumes.md).

1. To access the ONTAP CLI, establish an SSH session on the management port of the Amazon FSx for NetApp ONTAP file system or SVM by running the following command. Replace `management_endpoint_ip` with the IP address of the file system's management port.

   ```
   [~]$ ssh fsxadmin@management_endpoint_ip
   ```

   For more information, see [Managing file systems with the ONTAP CLI](managing-resources-ontap-apps.md#fsxadmin-ontap-cli). 

1. Create a LUN using the **lun create** NetApp CLI command, replacing the following values:
   + **`svm_name`** - The name of the storage virtual machine (SVM) providing the iSCSI target. The host uses this value to reach the LUN.
   + **`vol_name`** - The name of the volume hosting the LUN.
   + **`lun_name`** - The name you want to assign to the LUN.
   + **`size`** - The size, in bytes, of the LUN. The maximum size LUN you can create is 128 TB.
**Note**  
We recommend that you use a volume at least 5% larger than your LUN size. This margin leaves space for volume snapshots.
   + **`ostype`** - The operating system of the host, either `windows_2008` or `linux`. Use `windows_2008` for all versions of Windows; this ensures the LUN has proper block offset for the operating system and optimizes performance.
**Note**  
We recommend enabling space allocation on your LUN. With space allocation enabled, ONTAP can inform your host when the LUN is out of capacity and can reclaim space as you delete data from the LUN. 

   For more information, see [https://docs.netapp.com/us-en/ontap-cli-9121/lun-create.html](https://docs.netapp.com/us-en/ontap-cli-9121/lun-create.html) in the NetApp ONTAP CLI documentation.

   ```
   > lun create -vserver svm_name -path /vol/vol_name/lun_name -size size -ostype ostype -space-allocation enabled
   ```

   ```
   Created a LUN of size 10g (10737418240)
   ```

1. Confirm the LUN is created, online, and mapped.

   ```
   > lun show
   ```

   The system responds with the following output:

   ```
   Vserver   Path                            State   Mapped   Type         Size
   --------- ------------------------------- ------- -------- ------------ --------
   svm_name 
             /vol/vol_name/lun_name          online  unmapped windows_2008 10GB
   ```

## Next steps
<a name="iscsi-next-steps"></a>

Now that you have created an iSCSI LUN, the next step in the process of using an iSCSI LUN as block storage is to map the LUN to an `igroup`. For more information, see [Provisioning iSCSI for Linux](mount-iscsi-luns-linux.md) or [Provisioning iSCSI for Windows](mount-iscsi-windows.md).