4 

Volume Operations

This chapter describes the volume management offered by Nexsan iSeries Manager. Nexsan iSeries Manager enables you to create and operate volume built from physical storage attached to the Nexsan iSeries.

Displaying Storage

Volume operations are performed from the Storage View Main Window (Figure ‎4-1) or from the Advanced Volume Creation Window (Figure ‎4-5).

To display the storage view window:

	Click on Storage in the navigation pane.

The Available Storage Devices and Subdisks Details (partitioned disks) panels appear in the main window.

Figure ‎4-1. Storage View Focus

To display disk details for a specific storage device connected to one of the devices in a cluster:

1.	Click on the storage name in the tree.

Connected Storage devices are displayed in the right-hand of the screen.

2.	Clicking on a storage device will launch its management application.

Figure ‎4-2. Managing Connected Storage Devices

To display RAID Properties for a storage item:

	Right click on the tree item and select RAID Properties.

The RAID Properties window appears.

To display General and Details for a storage device:

	From the List of Available Storage Devices, right click and select Properties.

The General and RAID Details tabs are displayed.

Figure ‎4-3. General & RAID Details for Storage Devices

To display the Advanced Volume Creation Window:

1.	From the Quick Launch: Configure > Create Volume > Advanced…

Figure ‎4-4. Accessing Advanced Volume Operations

Figure ‎4-5. Advanced Volume Creation Window

Storage Properties

To display or modify available storage properties:

1.	Select the desired storage device by clicking on its name from the Available Storage Devices panel (Figure ‎4-7).

2.	Right click and select Properties.

Figure ‎4-6. Disk Properties Menu

The Disk Properties dialog box opens. If subdisks exist, you can view them by clicking on the subdisks tab (Figure ‎4-8).

3.	The fields Alias, Information, Write Cache Enabled and Allocable are editable

4.	Configure parameters and click OK.

Figure ‎4-7. General Tab - Disk Properties

Figure ‎4-8. Subdisks Tab - Disk Properties

Creating Volumes

This section describes the steps to create the virtual volume from the actual physical volumes. There are two main steps to volume creation:

1.	Creating the virtual volume from a physical disk. Volumes can be made from the whole physical disk, or partitioned into subdisks.

2.	Exposing the virtual volume. Volumes cannot be accessible by servers until they have been exposed. For information on exposing the volumes, see Volume Exposure & Targets.

Express Volume Creation

Express volume creation allows you to create and expose a volume from one dialog box.

To express create volumes:

1.	From the Quick Launch: Configure > Create Volume

Figure ‎4-9. Quick Launch - Create Volume

The Create Volume window appears.

Figure ‎4-10. Create Volume

 

2.	Select a storage resource group from the list.

3.	Assign an alias for the volume you are about to create.

4.	If you want to create a mirrored volume check the Mirror checkbox.

5.	Select a storage from which to create this volume from the list of available storage types/pools.

6.	Specify the size of the volume to create. Select the units for the volume MB, GB or TB. Either fill in a value or use the slider.

7.

You can let the system automatically create a new Target for the volume by checking 'Auto Target'. If you want to manually select an existing target to expose this volume on unselect 'Auto Target' and select a target from the drop down list. If you want to create a new target for the volume, click New Target.

8.	You can let the system select a LUN by checking 'Auto LUN' or specify a LUN for the target by filling in the desired value.

9.

Click OK.

Creating Volumes from the Whole Physical Disk

Volumes must be exposed in order for them to be used by FS Applications.

Note: Only disks that don’t have subdisks configured on them, or are not being used, can be directly exposed.

 

To create a volume from the whole physical disk:

1.	From the list of available storage devices, select the physical volume to expose.

2.	Right click the mouse and select Expose… Volume Exposure is discussed below in Creating Subdisks (LUN Carving).

Figure ‎4-11. Expose Volume

Creating Subdisks (LUN Carving)

Volumes can be created from partitioned disks (subdisks).

Note: Subdisks have start block and end block addresses within the disk in hexadecimal form.

 

To create a subdisk:

1.	Select the disk you want to partition from the list of available disks (Figure ‎4-11).

The disk appears in the Subdisks Details pane on the right. The available space on the disk is listed as free.

2.	Right click and select Create Subdisk from the open menu (Figure ‎4-12).

The Create Subdisk dialog box opens.

Figure ‎4-12. Create Subdisk

In the Create Subdisk dialog box:

3.	Enter the Subdisk Alias. If no alias is entered, Nexsan iSeries Manager will provide a default alias.

4.	Enter the Size Required for the subdisk required in MB, GB or TB.

Select the Starting Address for the subdisk by checking either Automatic Start Address or Supply Start Address (and enter starting address).

By selecting Supply Start Address, you must enter the start address in hexadecimal form in the Start Address field. The next available start address for subdisks side by side is the first subdisk end address plus disk block size.

Note: By selecting Automatic Start Address, Nexsan iSeries Manager will choose the smallest available space to start for your subdisk.

 

5.

Click OK.

The disk in the Subdisk Details pane is repartitioned to include the new subdisk (Figure ‎4-13). For each subdisk, the following information is listed (next to the graphical representation of the partition): subdisk alias, size of the subdisk and its relative percentage of the disk.

Figure ‎4-13. New Subdisk (Subdisks Details Pane)

Volume Exposure & Targets

Every volume that is exposed is connected to a target. When exposing volumes, you can create a new target or use an existing one. Basically there are two things you can do:

	Expose a volume by creating a new target for it.

	Expose a volume by using an existing target.

Exposing Volumes and Creating a New Target

To expose a volume and create a new target:

1.	From the Create Volume window, select the volume to expose.

2.	Click Expose .

The Expose Volume dialog box opens.

Figure ‎4-14. Expose Volume

3.	From the Expose Volume dialog box, click New Target.

The New Target dialog box opens.

Figure ‎4-15. New Target

4.	Enter the Target Alias and Target Name (target WWUI).

5.	Select value for Nexsan iSeries Exposed on (the Nexsan iSeries on which to expose the target).

6.	Select the Default Access rights for the target. Choose from Read/Write (RW), Read Only (RO) or Not Available (N/A). The default is RW.

 

Note: A target alias is an internal identifier and can be modified later.  A target name is the WWUI of the target and for external use when connecting to an initiator and cannot be modified.  A target name must be in lower case letters.  A target alias and name can be the same.

 

7.

Click OK.

The New Target dialog box closes and the new target appears in the Expose Volume dialog box (Figure ‎4-16).

Figure ‎4-16. New Target Listed in Expose Volume Dialog Box

8.	Assign a LUN and click OK. The LUN can be any value between 0 and 255.

The exposed volume disappears from the Create Volume window and appears under Targets/LUs in the navigation pane (Figure ‎4-17). The attached volume is now exposed on the target to all initiators as a read-write volume. To Restrict refer to Volume Security.

9.	Targets without attached volumes are indicated by a blue exclamation mark on the left of the target name.

10.	Targets with an attached volume are indicated by a green check mark on the left of the target name.

Figure ‎4-17. New Target Listed in Navigation Pane

Creating a New Stand-Alone Target

Note: Targets can be created without a volume associated with it. These targets will have no initial associated LUNs and will not be exposed to hosts when first created.

 

To create a new stand-alone target:

1.	From the Navigation pane, right click the desired Cluster and select New > Target…

Figure ‎4-18. Create New Target

2.	Enter the Target Alias and Target Name (target WWUI).

3.	Select value for Nexsan iSeries Exposed on (the Nexsan iSeries on which to expose the target).

4.	Select the Default Access rights for the target. Choose from Read/Write (RW), Read Only (RO) or Not Available (N/A). The default is RW.

Note:  A target alias is an internal identifier and can be modified later.  A target name is the WWUI of the target and for external use when connecting to an initiator and cannot be modified.  A target name must be in lower case letters.  A target alias and name can be the same.

Figure ‎4-19. New Target Alias and Name

5.

Click OK.

The new target is listed under Exposed Volumes in the Navigation pane. The target is displayed by its alias. Move the mouse over the alias to display the target name and exposing Nexsan iSeries.

Figure ‎4-20. New Target in Navigation Pane

Exposing Volumes on Existing Targets

To expose a volume on existing targets:

1.	From the Create Volume window (Figure ‎4-11), select the volume to expose, and click Expose .

The Expose Volume dialog box opens.

Figure ‎4-21. Expose Volume

2.	Select an existing Target from the list.

3.	Assign a LUN for the target. The LUN should be unique for a specific target.

4.

Click OK.

Note:  A LUN value is any number between 0 and 255.  A snapshot volume must be exposed on the same Nexsan iSeries as the source volume.

Modifying & Displaying Target Properties

You can modify/display some target properties.

To modify or display target properties

1.	In the Navigation pane, select the target.

2.	Right click on the target and select Properties...

Figure ‎4-22. Target Properties

The Target Properties dialog box opens (Figure ‎4-23).

You may edit the following target properties.

	Target Alias, Nexsan iSeries Exposed, Default Access (General tab)

	User Name, Password (Authentication tab)

Figure ‎4-23. Target Properties – General Tab

Table ‎4-1. General Target Properties

Parameter	Description
Target Alias	User-given alias for target
Target Name	WWUI of target
Status	Status of target
Number of LUs	Number of LUs associated with the target
Nexsan iSeries Exposed On	Nexsan iSeries on which the target and its attached LUs are exposed
Default Access	Default Access to the target RW – read-write RO – read only NA – no access
Number of SCSI ports	Number of SCSI ports on Nexsan iSeries
Port Name	target port name

Figure ‎4-24. Target Properties – Details Tab

Table ‎4-2. Target Details

Parameter	Description
Number of Login Failures	Number of Login attempts that failed
Last Failure Time	Time of last failed login attempt
Last Failure Type	Type of login failure options: other; redirect; authorize; authenticate; negotiate
Last Failed Initiator Name	Name of last initiator that failed to login
Last Failed Initiator IP	IP address of last initiator that failed to login

 

To configure target authentication parameters for iSCSI initiators:

1.	In the Navigation pane, right click on the target and select Properties (Figure ‎4-22).

The Target Properties dialog box appears.

2.	Select the authentication tab (Figure ‎4-25).

3.	Enter the desired User Name and Password.

4.

Click OK.

Figure ‎4-25. Target Properties – Authentication Tab

Note: If no password is provided, no target authentication properties are applied. Passwords must be 12-16 character in length.

Advanced Volume Creation

Advanced volume operations are performed from the Advanced Volume Creation window (Figure ‎4-27).

Access the Advanced Volume Operations window as follows:

1.	From the Nexsan iSeries Manager menu bar: Configure > Advanced Volume Operations

Figure ‎4-26. Accessing Advanced Volume Operations

The Advanced Volume Creation window appears.

Figure ‎4-27. Advanced Volume Creation

Creating Concatenated Volumes

You can concatenate volumes across storage devices to create larger virtual volumes. Concatenated volume can be created from any two (or more) disks or subdisks of equal block size.

To concatenate volumes:

1.	Navigate to the Advanced Volume Creation window (Figure ‎4-27).

2.	Using the Ctrl key select all the subdisks (children) to use for the concatenated volume (Figure ‎4-28).

Note: The disks/subdisks must be of the same block size.

 

Figure ‎4-28. Subdisks Selected

3.	Click Concatenation icon  to create the concatenated volume.

The New Volume dialog box opens (Figure ‎4-29).

Figure ‎4-29. New Volume

4.	Enter the Volume Alias of the concatenated volume. If no alias is entered, a default alias will be assigned.

5.

Click OK.

The concatenated volume appears in the right pane of the Create Volume window (Figure ‎4-30). The blue exclamation mark signifies that the volume is internal (not exposed to hosts).

Figure ‎4-30. Concatenated Volume

Creating Mirrored Volumes

A mirrored volume is written into all the volumes (copies). The read load is balanced between each copy. Mirrored volumes can be created from two to four disks or subdisks of equal block size. The size of the mirror is determined by its smallest child volume.

Note: Mirrored volumes should be located on different physical disks.

 

To create a mirrored volume:

1.	Navigate to the Advanced Volume Creation window (Figure ‎4-27).

2.	Using the Ctrl key select the subdisks (children) (Figure ‎4-31) to use for the mirrored volume.

Note: The disks/subdisks/volumes must be of the same block size.

 

Figure ‎4-31. Subdisks Selected for Mirror

3.	Click the Mirror icon  to create the mirrored volume.

The New Mirror Volume dialog box opens.

Figure ‎4-32. New Mirror

4.	Enter the volume alias of the mirrored volume. If no alias is entered, a default alias will be assigned.

5.

Click OK.

The mirrored volume appears in the right pane of the Create Volume window (Figure ‎4-30). The blue exclamation mark next to the mirror icon  signifies that the volume is internal (not exposed to hosts).

Figure ‎4-33. Mirrored Volume

Creating Striped Volumes

A striped volume has data written equitably across two or more disks to provide higher read/write rates. Throughput increases with the number of disks within a striped volume.

Note: Children volumes within a striped volume need to be on different disks/RAID sets to realize the benefits of striping.

 

Create a striped volume using two or more disks/subdisks/volumes of the same size and block size. A striped volume has a stripe unit size. The stripe unit size is the size of the data chunk read/written on each of the stripe’s children.

To create a striped volume:

1.	Navigate to the Advanced Volume Creation window (Figure ‎4-27).

2.	Using the Ctrl key select the subdisks (children) (Figure ‎4-34) to use for the striped volume.

Note: The disks/subdisks must be of the same block size.

 

Figure ‎4-34. Subdisks Selected for Stripe

3.	Click the Stripe icon  to create the striped volume.

The New Stripe Volume dialog box opens (Figure ‎4-35).

Figure ‎4-35. New Stripe

4.	Enter the Stripe Unit Size to use in creating the striped volume.

5.	Enter the Volume Alias of the striped volume. If no alias is entered, a default alias will be assigned.

6.

Click OK.

The striped volume appears in the right pane of the Create Volume window (Figure ‎4-36). The blue exclamation mark next to the striped volume icon  signifies that the volume is internal (not exposed to hosts). As the subdisks are incorporated into the striped volume, the green check marks to the left of the subdisk name change to blue exclamation marks.

Figure ‎4-36. Striped Volume

Transparent Volumes

You can create a transparent volume from a disk/tape resource for direct exposure.

Note: Transparent volumes are mainly used for connecting tape devices to the Nexsan iSeries.

 

Certain vendor storage devices have vendor-specific SCSI commands. To support these commands across the Nexsan iSeries, you can convert these storage devices and their contained data to transparent volumes.

Notes:  Only a full, not partitioned disk can be used to create a transparent volume.  Unlike all other types of volumes, Transparent volumes cannot be used in further volume hierarchies.  Transparent volume must maintain the physical LUN number of the physical disk it was configured on.  You cannot define ACL for transparent volumes. It is always R/W.  Unexposing a transparent volume (deleting LU) will automatically delete the volume.

 

To create a transparent volume:

1.	Navigate to the Advanced Volume Creation window (Figure ‎4-27).

2.	Select the disk to use for the transparent volume.

The Transparent icon  is now available.

3.	Click the Transparent icon to create new transparent volume.

The New Transparent Volume dialog box opens.

Figure ‎4-37. New Transparent Volume Dialog Box

4.	Enter the Volume Alias of the transparent volume. Note: If you leave the alias blank, the system will assign the disk alias.

5.

Click OK.

The transparent volume appears in the right pane of the Create Volume window. The blue exclamation mark next to the transparent icon  signifies that the volume is internal (not exposed to hosts).

Figure ‎4-38. Transparent Volume

Creating a Mirror over Striped Volumes

 

Note:  All striped or mirrored volumes in the ground level hierarchy must be the same size.  All volumes in a hierarchy must have the same block size.

 

To create a mirror over striped volume:

1.	Select the Stripe children (Figure ‎4-39).

Figure ‎4-39. Striped Volumes Selected

2.	Click the Mirror icon  to create the mirrored volume.

The New Mirror Volume dialog box opens.

Figure ‎4-40. New Mirror Volume

3.	Enter the Volume Alias for the mirrored volume. If no alias is entered, a default alias will be assigned.

4.

Click OK.

The new mirrored volume appears in the Unexposed Volumes pane (Figure ‎4-41).

Figure ‎4-41. Mirror over Stripe

Creating a Stripe over Mirrored Volumes

Notes:  All striped or mirrored volumes in the ground level hierarchy must be the same size.  All volumes in a hierarchy must have the same block size.

 

To create a stripe over mirrored volume:

1.	Select the Mirror children (Figure ‎4-42).

Figure ‎4-42. Mirrored Volumes Selected

2.	Click the Stripe icon  to create the mirrored volume.

The New Stripe Volume dialog box opens.

Figure ‎4-43. New Stripe Volume

3.	Enter the Volume Alias of the striped volume. If no alias is entered, a default alias will be assigned.

4.

Click OK.

The new striped volume appears in the Unexposed Volumes pane (Figure ‎4-44).

Figure ‎4-44. Stripe over Mirror

Displaying Volume Hierarchies

You can display exposed and unexposed volume hierarchies. The hierarchy levels are displayed from the volume children down to the storage device level.

To display a volume hierarchy:

1.	Navigate to the Advanced Volume Creation window (Figure ‎4-27).

2.	Double click on the selected volume.

The first level opens under the top level volume.

3.	To view subsequent layers, double click on the volume children until the desired hierarchy level. The hierarchy can be opened to the storage device or subdisk level.

Figure ‎4-45. Expanded Hierarchy