Creating Volumes

When you create a volume, you specify the volume size (reported size that is seen by initiators), snapshot reserve, access control information, and other attributes. An iSCSI target name will be automatically created for the volume.

To create a volume, click:

Volumes > Create volume

The Create Volume - General Settings dialog box appears (Figure 1: Create Volume - General Settings ).

Figure 1: Create Volume - General Settings

You can specify information in the following fields:

• Volume name – Unique name, up to 64 alphanumeric characters (including periods, hyphens, and colons), used to identify the volume for administrative purposes. The volume name appears at the end of the iSCSI target name that is generated for the volume. Host access to the volume is always through the iSCSI target name, not the volume name.
• Description – The volume description is optional.
• Storage pool – All volume data will be restricted to the members that make up the pool. By default—or if only one pool exists—the volume will be assigned to the default pool. If multiple pools exist, you can assign the volume to a different pool. See Storage Pool Management for information about setting up pools.

Click Next to display the Create Volume – Space Reserve dialog box (Figure 4: Create Volume - iSCSI Access Policy ).

Figure 2: Create Volume - Space Reserve

Specify information in the following fields:

• Volume size – This is the reported size of the volume as seen by iSCSI initiators.
  Be sure to select the correct unit (by default, gigabytes). The minimum volume size is 15 MB. In addition, volume sizes are rounded up to the next multiple of 15.
  
  The largest volume size you can specify appears next to the Volume size field. This value depends on the volume’s thin provisioning setting.

Note: For a standard volume (without thin provisioning), the volume reserve (allocated space) is the same as the reported size. For a thin-provisioned volume, the volume reserve will be less than or equal to the reported size.

• Thin provisioned volume – Select this checkbox to enable thin provisioning on the volume. When selected, slider bars appear in the Reported volume size panel (Figure 3: Volume Create - Space Reserve - Thin-Provisioned Volume ). Use them to modify the following default thin-provisioning values:

See Understanding Thin Provisioning for more information.

Figure 3: Volume Create - Space Reserve - Thin-Provisioned Volume

• Snapshot reserve – If you want to create snapshots of the volume, specify the amount of pool space to reserve for snapshots, as a percentage of the volume reserve. The default is the group-wide volume setting. If you enter a value, this space is reserved even if you never create a snapshot.

To change the snapshot space recovery policy or warning threshold (the defaults are the group-wide volume settings), you must modify the volume’s snapshot settings after creating the volume, as described in Modifying Snapshot Settings.

The values in the storage pool space tables shown in Figure 2: Create Volume - Space Reserve and Figure 3: Volume Create - Space Reserve - Thin-Provisioned Volume change to show how creating the volume will affect the pool space utilization, as described in Table 1: Storage Pool Space Table Values for Volumes.

If creating the volume will exceed the capacity of the pool, the table cell showing free pool space will turn red.

Click Next to display the Create Volume – iSCSI Access Policy dialog box (Figure 4: Create Volume - iSCSI Access Policy ), which enables you to create an access control record for the volume.

Figure 4: Create Volume - iSCSI Access Policy

Access control records are used to restrict volume access to hosts that supply a recognized CHAP user name and password (or "secret") or that match an IP address or iSCSI initiator name (or any combination of the three).

To create an access control record that will apply to the volume and its snapshots, in the Create Volume – iSCSI Access Policy dialog box, click Restricted access and one or more of the following:

• Authenticate using CHAP user name – Restricts access to hosts that supply the specified CHAP user name (and its associated password or "secret"). The user name must match a local CHAP account or an account on an external RADIUS server, as described in Using CHAP to Control iSCSI Access to Volumes.
• Limit access by IP address – Restricts access to hosts with the specified initiator IP address (for example, 12.16.22.123). Use asterisks for "wildcards," if desired (for example, 12.16.*.*). An asterisk can replace an entire octet, but not a digit within an octet.
• Limit access to iSCSI initiator name – Restricts access to hosts with the specified iSCSI initiator.

Note: If using IP addresses or iSCSI initiator names to restrict access, be sure to create an access control record for each IP address or iSCSI initiator name presented by an authorized host.

If you do not want to create an access control record at this time, select No access. No host will be allowed access to the volume until you create a record. You can set up access control records or modify records after creating the volume, as described in Managing Access Controls for Volumes and Snapshots.

After specifying the access information, click Next to display the Create Volume - Summary dialog box (Figure 5: Create Volume - Summary ).

Figure 5: Create Volume - Summary

If the configuration is correct, click Finish to create the volume. To make changes, click Back.