Volumes provide a way to allocate storage available in a storage pool and share it over the network. The Volumes and LUNs section of SoftNAS allows you to create, edit, remove and manage storage volumes and their snapshots.

1. Volumes Grid

The Volumes Grid displays the list of storage volumes in a tabular grid format. The volume table has the following fields.

2. Creating a New Volume

• From the Volumes and LUNs page, Click the Create button in the toolbar.  The Create Volume dialog will be displayed.
• Enter the name of the volume in the Volume Name text entry box.

• To select the storage pool where the storage space for the volume has to be reserved, click the Storage Pool button.

The Choose a Storage Pool dialog will be displayed.

• Select the required storage pool from the list of available storage pools.
• Click the Select Pool button.
• Back in the Create Volume dialog, the name of the selected storage pool will be displayed in the Storage Pool field.

• Select the type of the volume from the Volume Type section. The available volume types are File System (NFSv4, NFSv3, and/or, CIFS) or Block Device (iSCSI LUN).
  

  If you want to share the volume via iSCSI, then choose Block Device instead of accepting the default File System volume type.

   
  

• One-click Sharing - SoftNAS supports one-click sharing during Volume creation. Choose the appropriate sharing option checkboxes to Export to NFS and/or Share via CIFS, Share Via AFP as appropriate. Verify the type of one-click sharing selected. The available options are Export via NFS, Share via CIFS for the File System volume type and Share as iSCSI LUN for Block Device volume type.

Block Device (iSCSI LUN)

• If Block Device (iSCSI LUN) is selected during Volume Creation, the LUN Targets tab is displayed. You can use the LUN Targets tab to select an available iSCSI LUN Target as part of your create Volume workflow.
• You are prompted to select the appropriate iSCSI LUN Target.

• Select the type of the storage provisioning option. The available options include Thin Provision - Dynamically allocate space as it is needed and Thick Provision - Pre-allocate space from storage pool now.

Thin Provision and Thick Provision

• Thin-provisioning allows a volume to acquire storage from its Storage Pool on an as-needed basis, as new data is written to the volume. Thin-provisioning enables many volumes to share a storage pool without an upper limit being placed on the volume itself (the only upper limit to the volume's size is available space in the pool).
• Thick-provisioned volumes reduce the amount of space available in the Storage Pool by reserving this space for use by a specific volume. When a thick-provisioned volume reaches its maximum volume size, no more data can be written and a volume full error will be returned for writes to a full volume. Thick-provisioned volumes can be re-sized at any time to add space (or return space to the storage by by reducing the volume size).

Volume Size - Thick Provision

• If you select the type of the storage provisioning option as Thick Provision in the previous step, then specify the size of the volume in the Volume Size field and select the size unit.

• Once a Storage Pool has been selected for a thick-provisioned volume, the amount of available space to allocate is displayed below the Volume Size field, as shown in the example below. 
• The Volume Size value can be any valid numeric value; e.g., 10, 12.5, 100.0, 1.25 

• The Size Units selector is used to choose the units for the Volume Size. Select the required size unit from the drop down list. The available units include MB – Megabytes, GB - Gigabytes (default) and TB – Terabytes. 

Storage Optimization

• Select the required option for storage optimization in the Storage Optimization Options section. The available options are Compression and Deduplication.

• The Compression type saves disk space, at the expense of additional CPU overheads for each read and write request (to decode and encode the data). Depending on how compressible the data is, it is common to see data compression rates up to 50% or more.

• The Deduplication type eliminates duplicates, but consumes more memory space. For certain types of data (e.g., Windows virtual machine images, which are highly-redundant in virtual desktop applications), deduplication can save up to 80% on storage requirements by eliminating duplicate data. Each time a duplicate data block is to be written, a pointer to the existing duplicate block is created instead, along with increasing the duplicate block reference count. To make these operations as fast as possible, a table of deduplicated blocks is maintained. A hash table of deduplicated blocks is kept in memory to make lookups very fast. When a duplicate block is read, it is usually in cache memory and is simply returned with no disk I/O required.

• Select Sync Mode from drop down.  The available options are Standard, Always, and Disabled.

• The Standard option is the default option.  Synchronous transactions are written to the intent log and all drives written are flushed to ensure the data is stable (not cached by device controllers).

• The Always option is for the ultra-cautious.  Every file system transaction is written and flushed to stable storage by a system call return.
  

   This will result in a large performance penalty

• The Disabled option disables synchronous requests.  File system transactions only commit to stable storage on the next DMU transaction group commit which can be many seconds.
  

  This will result in the highest performance but increases potential data loss

Snapshots

• Optionally, you can click the Snapshots tab to configure the same.  The Snapshots section of the dialog will be displayed.
  
  

1. To enable the scheduling of volume snapshots, check the Enable scheduled volume snapshots box.
   
   
2. To enable replication, check the Enable replication box.
   
   
3. Select the type of snapshot schedule from the Snapshot Schedule drop down list. The available options include are Default, 24 x 7, and Maximum Snapshots.
   
   
4. In the Scheduled Snapshot Retention Policy section, set the maximum number of scheduled snapshot copies to maintain in the Hourly, Daily and Weekly fields by either manually entering the value or by using the scroll bar to increase or decrease the value.  You should also set the Minimum size threshold (MB).
   
   

5. Once configuration is complete, click the Create button.

3. Editing a Volume

You can edit any selected volume. To do so, simply follow the steps given below.

• Select the volume that you wish to edit in the Volumes list.  Click the Edit button in the toolbar.  The Edit Volume dialog will be displayed. 

1. Select the type of the storage provisioning option. The available options include Thin Provision - Dynamically allocate space as it is needed and Thick Provision - Pre-allocate space from storage pool now. By default, volumes are thin-provisioned.

   If you select the type of the storage provisioning option as Thick Provision, then specify the size of the volume in the Volume Size field.  When Thick Provision is selected the Volume Size specifies how much space is to be pre-allocated to the volume. Space is determined by entering a Volume Size amount as a floating point value, along with choosing the Size Units.
2. Select the required option for storage optimization in the Storage Optimization Options section.  The available options are Compression and Deduplication.
   
   
3. Select the Sync Mode. The available options are Standard, Always, and Disabled.
   
   
4. Once configurations are complete, click the Save button.

• Click the Snapshots tab. The Snapshots section of the dialog will be displayed. 
• Edit the parameters of the Snapshots configuration as necessary.
• Once configurations are complete, click the Save button.  The changes made to the volume will be updated.

4. Deleting a Volume

You can delete an unused volume. To do so, simply follow steps given below.

• Select the volume that you wish to delete in the Volumes list.
• Click the Delete button in the toolbar.  The Delete Confirmation Required dialog will be displayed.
• Enter the text "I Approve" in the text entry box.
• Click the Delete Permanently button.
  
  

9. Viewing Overview Chart 

You can view the summarized details of volume in the Overview Chart.

• To do so, simply navigate to the Overview tab in the left corner, at the end of the Volumes panel.  The Volume Usage Chart with a bar chart summarizing storage usage by volume will be displayed. 
• Move the mouse cursor over the top of a volume's bar. You can view the a summary of usage in a tooltip popup window.
• To view the Overview Chart of a selected volume, click that volume to select it in the Volumes list. 

The Overview Chart of the selected volume will be displayed.