Managing iSCSI logical units
This section describes how to manage iSCSI logical units.
Viewing the properties of iSCSI logical units
You can view the iSCSI logical units in the NAS Manager.
Navigate to to display the iSCSI Logical Units page.
The following table describes the fields on this page:
Field/Item Description EVS/File System Selector for EVS and File System where LUs reside, or where LUs can be created. To switch to a different EVS/File System, click change. change Click change to switch to a different EVS/File System. Filter Use Filter to display a subset of the iSCSI Logical Units. The options are: - Alias - name of the LU.
- File System - the file system for the LU.
- Path - the path of the LU.
- Used in Target - the target of the LU.
Filter Click Filter to display a subset of the iSCSI Logical Units. Alias Name of the LU. File System:Path The file system and path for the LU. NoteLUs appear as regular files in server file systems.Size Size of the LU. This value cannot exceed the amount of available free space on the configured file system. Status Indicates of the LU status, usually whether the LU is mounted. NoteThe status will display Unmounted while an LU is being created asynchronously, and will then display Mounted once the creation has completed.Used in Target Displays the target. mount Select an unmounted LU and click mount to mount the LU. unmount Select a mounted LU and click unmount to unmount the LU. delete Deletes the selected iSCSI LUs. add Opens the Add iSCSI Logical Unit page where you can create a new iSCSI LU. details Opens the iSCSI Logical Unit Details page for the selected LU. iSCSI Targets Advances to the iSCSI Targets settings page. iSCSI Initiator Authentication Advances to the iSCSI Initiator Authentication settings page.
Adding iSCSI logical units
You can add iSCSi Logical Units in the NAS Manager.
Navigate to and then click add to display the Add iSCSI Logical Units page:
The following table describes the fields on this page:
Field/Item Description EVS/File System Displays the Virtual Server and file system on which to create the Logical Unit. change Click to open the Select a File System page where you can select a different file system. Alias The name of the logical unit. The maximum number of characters is 255. Path to File The path where the logical unit resides. browse can be used to assist in finding the desired path of a predefined Logical Unit. File Already Exists Choose this option if the file already exists. Create File Choose this option if the file does not exist. Size Size of the LU. This value cannot exceed the amount of available free space on the configured file system. Create path to file if it does not exist Creates the path specified in the Path to File field. Comment Allows you to provide descriptive information about the Logical Unit.
iSCSI Targets Advances you to the iSCSI Targets page, which allows you to add, modify, and delete iSCSI Targets. iSCSI Targets appear to iSCSI initiators as different storage devices accessible over the network.
If necessary, change the EVS and/or file system.
The EVS name displayed indicates the EVS and file system to which the LU will be added. Click change to select a different EVS or file system.Specify the Logical Unit alias.
In the Alias field, enter a name for the LU.If the path to the file already exists, specify the path to the Logical Unit. When entering a path for an LU file that already exists, use the following procedure:
Choose the file.
Click browse to display a dialog that will allow you to select the file for the LU. Alternatively, you can enter the path name of the file (including the extension) and not use the browse button.Select the File Already Exists radio button.
Optionally, add a comment.
Using the comment field, you can provide descriptive information about the LU.Save the Logical Unit definition.
Click OK to add the LU.
If the path to the file does not already exist, specify to create the path to the Logical Unit. There are several steps to complete when creating a new file for use as an LU:
Choose the path for the file.
Click browse to display a dialog that will allow you to select the directory for the LU file. The name of the file as well as the directory need to be specified. The file does not need an extension; iscsi is appended automatically. Alternatively, you can enter the file name and path (including the extension) and not use the browse button.Select the Create File radio button.
Specify the logical unit size.
Using the Size field and the drop-down list, specify the size of the LU file.Fill the Create path to file if it does not exist check box.
Optionally, add a comment.
Using the Comment field, you can provide descriptive information about the LU.Save the logical unit definition.
Click OK to add the LU.
Modifying an iSCSI logical unit
You can modify an iSCSI logical unit in the NAS Manager.
Navigate to .
Select the check box next to the iSCSI logical unit to modify and then click details.
The following table describes the fields on this page:
Field/Item Description EVS/File System Displays the EVS and file system hosting the LU.
File System Free Capacity The amount of free space available in the file system. Status Indicates whether the LU is mounted or unmounted. It is possible to mount/unmount a LU while its underlying file system remains mounted. If the LU is not mounted, click mount to mount the LU. If the LU is mounted, click unmount to unmount the LU.
Filling the Ensure the underlying file system exists when mounting check box will ensure that the underlying file system exists when the LU is mounted.
Alias Name of the LU. You can change this name. Path to File The complete file system path to the LU file.
NoteLUs appear as regular files in server file systems.Comment Use to provide descriptive information about the LU. Size Size of the LU. This value cannot exceed the amount of available free space on the configured file system.
iSCSI Targets Opens the iSCSI Targets page, in which you can add, modify, and delete iSCSI Targets. Modify the fields as necessary.
Click OK.
Deleting an iSCSI logical unit
You can delete an iSCSI logical unit in the NAS Manager.
Navigate to to display the iSCSI Logical Units page.
Select the check box next to the logical unit to delete and then click delete.
Click OK to confirm the deletion.
Backing up iSCSI logical units
Only a client connected to the LU through its Target can access and backup individual files and directories contained in the LU. LUs back up as normal files on a server file system.
To back up an iSCSI LU:
Procedure
Disconnect the iSCSI Initiator from the Target.
Unmount the iSCSI Logical Unit.
To unmount the iSCSI LU, you can use the following CLI command:
iscsi-lu unmount <name>
Where <name> is the name of the iSCSI LU.
Back up the Logical Unit to a snapshot or backup device.
For safety, you should either back up the iSCSI LU to a snapshot or to another backup device.
Mount the Logical Unit.
To mount the iSCSI LU, you can use the following CLI command:
iscsi-lu mount <name>
Where <name> is the name of the iSCSI LU.
Reconnect to the iSCSI Target using the iSCSI Initiator.
If necessary, rescan disks.
You may have to use Window’s Computer Manager rescan disks to make the LU reappear to clients.
Restoring iSCSI logical units
Procedure
Disconnect the iSCSI Initiator from the Target.
Unmount the iSCSI logical unit.
Use the following CLI command: iscsi-lu unmount <name>, where name is the name of the LURestore the logical unit from a snapshot or backup.
Mount the iSCSI logical unit.
Use the following CLI command: iscsi-lu mount <name>, where name is the name of the LU.Reconnect to the Target using the iSCSI Initiator.
If necessary, rescan disks in Computer Management.
Setting up iSCSI targets
An iSCSI target is a storage element accessible to iSCSI initiators. These targets appear to iSCSI initiators as different storage devices accessible over the network. The server supports a maximum of 32 iSCSI Targets per EVS and a maximum of 32 iSCSI sessions per Target.
Viewing the properties of iSCSI targets
You can view the properties of iSCSI targets in the NAS Manager.
Navigate to to display the iSCSI Targets page.
The following table describes the fields on this page:
Field/Item Description EVS Select the EVS on which the target will be hosted. change Click to select a different EVS. EVS iSCSI Domain Displays the iSCSI domain, which is the DNS domain used when creating unique qualified names for iSCSI targets. To set an iSCSI domain, enter a domain name and click apply. Alias Identifies the name of the target. Comment Additional information related to the target. Globally Unique Name The target’s name. The name is generated automatically by the server, and is unique across the globe. details Displays the details for the selected iSCSI target. add Advances to the Add iSCSI target page where you can add an iSCSI target. delete Deletes the selected iSCSI target. iSCSI Logical Units Advances to the iSCSI Logical Units settings page. iSNS Servers Advances to the iSNS Servers settings page. iSCSI Initiator Authentication Advances to the iSCSI Initiator Authentication settings page.
Adding iSCSI targets
You can add an iSCSI target in the NAS Manager.
Navigate to to display the iSCSI Targets page.
Click add to display the Add iSCSI Target page.
The following table describes the fields on this page:
Field/Item Description EVS The EVS that will host the iSCSI target. change Click to select a different EVS. iSCSI Domain The DNS domain used when creating the Globally Unique Name of an iSCSI target. Alias The name of the iSCSI target. This can be a maximum of 255 characters long. Comment Additional descriptive information about the target. Secret The password used to secure the target from any unauthorized access. The initiator authenticates against this password when connecting to the target. The secret should be greater than or equal to 12 characters, but less than 17 characters, in length. Although the secret may be between 1-255 characters in length, some iSCSI initiators will refuse to connect if the secret contains less than 12 characters or more than 16 characters. Enable Authentication By default, the check box is filled. Filling or clearing the check box enables or disables authentication. When authentication is disabled, initiators are permitted to connect to the target and its logical units without needing to know the target's secret. Access Configuration Enter the desired access configuration parameters. Refer to the Access Configuration table for details on how to define the Access Configuration List. Available Logical Units The list of Logical Units available to assign an iSCSI target. Selected Logical Units The list of Logical Units added to the target. Logical Unit Number Enter a Logical Unit Number. The number can be any unique number between 0 and 255. Specify the required information.
The iSCSI Domain, Alias, Available LUs, and Logical Unit Numbers are required, all other fields are optional.
Optionally, specify the Comment, Secret, and/or Access Configuration for the Target.
The following table provides syntax for the Access Configuration field:
What to type Means Blank or * All clients can access the target.
Specific address or name. Examples: 10.168.20.2, client.dept.company.com To deny access to a specific host, use the no_access or noaccess qualifier. For example, 10.1.2.38 (no_access) will deny access to the host with the IP address 10.1.2.38.
Only clients with the specified names or addresses can access the target. Partial address or name using wildcards. Examples: 10.168.*.*, *.company.com
To deny access to a specific host, use the no_access or noaccess qualifier. For example, 10.1.2.38(no_access) will deny access to the host with the IP address 10.1.2.38.
Clients with matching names or addresses can access the target. Click OK.
Adding a logical unit to an iSCSI target
You can add a logical unit to an iSCSI target in the NAS Manager.
Navigate to to display the iSCSI Targets page.
Select the check box next to the target and then click details to display the iSCSI Target Details page.
The following table describes the fields on this page:
Field/Item Description EVS Selector for EVS where LUs reside.
EVS iSCSI Domain Displays the iSCSI Domain, which is the DNS domain used when creating unique qualified names for iSCSI Targets. Alias Name of the iSCSI Target. Comment Additional information about the iSCSI Target. Secret Password used to secure the Target from any unauthorized access. The initiator authenticates against this password when connecting to the Target. The secret should be greater than or equal to 12 characters, but less than 17 characters, in length. Although the secret may be between 1-255 characters in length, some iSCSI initiators will refuse to connect if the secret contains less than 12 characters or more than 16 characters. Enable Authentication Enable authentication of the iSCSI Target. By default, the check box is not filled. Filling or clearing the check box enables or disables authentication.
When authentication is disabled, initiators are permitted to connect to the target and its LUs without needing to know the target's secret.
Access Configuration The access configuration parameters.
Available logical units The list of LUs available for assignment to the iSCSI Target. This list includes all LUs on the EVS. Some of these LUs may already be assigned to other targets. Selected LUN - LUN Name The list of LUs selected to be part(s) of the iSCSI Target. Logical Unit Number The number assigned to the LU (the LUN). Enter a Logical Unit Number in the range of 0-255. OK Saves configuration changes, and closes the page. cancel Closes the page without saving configuration changes. Select an LU from the Available Logical Units list, specify a number (0-255) in the Logical Unit Number field, and then click the right arrow to move the LU to the Selected Logical Units list.
NoteYou should make sure that the LU is not already assigned to a target.Click OK.
Modifying the properties of an iSCSI target
You can modify the properties of an iSCSI target in the NAS Manager.
Navigate to to display the iSCSI Targets page.
Select the check box next to the target to modify and then click details.
The following table describes the fields on this page:
Field/Item Description EVS Selector for EVS where LUs reside.
EVS iSCSI Domain Displays the iSCSI Domain, which is the DNS domain used when creating unique qualified names for iSCSI Targets. Alias Name of the iSCSI Target. Regenerate GUN Click to regenerate the Globally Unique Name (GUN). Comment Additional information about the iSCSI Target. Secret Password used to secure the Target from any unauthorized access. The initiator authenticates against this password when connecting to the Target. The secret should be greater than or equal to 12 characters, but less than 17 characters, in length. Although the secret may be between 1-255 characters in length, some iSCSI initiators will refuse to connect if the secret contains less than 12 characters or more than 16 characters. Enable Authentication Enable authentication of the iSCSI Target. By default, the check box is not filled. Filling or clearing the check box enables or disables authentication.
When authentication is disabled, initiators are permitted to connect to the target and its LUs without needing to know the target's secret.
Access Configuration The access configuration parameters.
Available logical units The list of LUs available for assignment to the iSCSI Target. This list includes all LUs on the EVS. Some of these LUs may already be assigned to other targets. Selected LUN - LUN Name The list of LUs selected to be part(s) of the iSCSI Target. Logical Unit Number The number assigned to the LU (the LUN). Enter a Logical Unit Number in the range of 0-255. The iSCSI Domain, Alias, Available LUs, and Logical Unit Numbers are required. Optionally, you can specify the Comment, Secret, and/or Access Configuration for the Target.
NoteOnce set, the iSCSI Domain cannot be changed, but it will be overridden/replaced if you later specify a new iSCSI Target with a different iSCSI Domain in the same EVS. The most recently specified iSCSI Domain overrides all previously-specified iSCSI Domains set for all previously added iSCSI Targets in the EVS.The following table describes what you can type in the Access Configuration field.
What to type Means Blank or * All clients can access the target.
Specific address or name. Examples: 10.168.20.2, client.dept.company.com To deny access to a specific host, use the no_access or noaccess qualifier. For example, 10.1.2.38 (no_access) will deny access to the host with the IP address 10.1.2.38.
Only clients with the specified names or addresses can access the target. Partial address or name using wildcards. Examples: 10.168.*.*, *.company.com
To deny access to a specific host, use the no_access or noaccess qualifier. For example, 10.1.2.38(no_access) will deny access to the host with the IP address 10.1.2.38.
Clients with matching names or addresses can access the target. Click OK.
Deleting an iSCSI target
You can delete an iSCSI target in the NAS Manager.
Navigate to .
Select the check box next to the target to remove and then click delete.
To confirm the deletion, click OK.