Managing RAID Groups

This help page provides information to guide you through the tasks included in managing RAID groups. It contains the following topics:

Overview

A RAID group can be considered as the RAID container for data protection and contain single or multiple parity groups. The parity groups are partitions of the RAID container. This way, multiple LUNs can be created in each RAID group, and ported out to the same or different servers. This allows granularity in LUN sizes being obtained from the RAID group.

If each partition (parity group) is assigned to the same host, there should be no contention for the RAID group's disk resources. This speeds up both read and write operations to the disk, and considerably improves system performance. However, instead of creating multiple parity groups, you can use the entire RAID group as a single parity group and create one large logical unit.

Note: The Simple Modular Storage system allows only one RAID group.

Displaying RAID Group Properties (back to top)

To display the properties of all of the RAID groups assigned to an array:

In the Arrays window, select an array of interest and click Show and Configure Array..
In the Arrays tree, expand the Groups menu and select RAID Groups. The RAID Groups window is displayed. It contains a table that lists the RAID groups that exist for the array. The following data for each RAID group is included in the table:
RAID level and parity group -- for example, RAID6(2D+2P)
The total capacity of the drives in each RAID group
The total free space in each RAID group
The type of drive(s) assigned to this RAID group

To display detailed data for a single RAID group, from the RAID Groups window, click the name of the RAID group you are interested in. The properties window for the selected RAID group is displayed. The window should look similar to the following illustration.

The Summary section of the RAID Group Window provides the following information:

Feature	Description
RAID Group	This is the name of the displayed RAID group. The default name is RG-000.) Note: The Simple Modular Storage System can have only one RAID group.
RAID level	This is the number of the RAID level (1-6) that has been assigned to the RAID group.
Parity Group	This is the name of the parity group that has been assigned
Number of Parity Groups	This is the number of parity groups that have been assigned to the RAID group (min - 1, max = ? )
Status	This is the status of expanded RAID group.
Capacity	This field displays both the total capacity of the hard drive(s) in the RAID group and the free space left on the drive(s).
Drive Type	This field displays the type of drive(s) contained in the RAID group. It can be either SAS or SATA. You cannot mix drive types within the same RAID group.
Priority	This is the priority that displayed RG Expansion or Host Access when expand RAID group.

Logical Units in a RAID Group (back to top)

In addition to the Summary area described above, The RAID Group window contains two tabs: Logical Units and Assigned drives.

Logical Units Tab (back to top)

The Logical Units tab is displayed by default. It displays a list of logical units in the RAID group and provides statistics about each LUN in a table within the tab. These are described in the following table.

Feature	Description
LUN	The LUN column in the table displays the name of the logical unit.
Capacity	The Capacity column displays the total size of the LUN in GB.
Stripe Size	The Stripe Size column displays the size of the data stripe on the HDU (hard drive unit) that is assigned to the LUN.
Cache Partition	This column displays the number of cache partitions assigned to the LUN (Range is 0 - nnn)
Pair Cache Partition	This column displays the number of cache partition pairs assigned to the LUN. The range is Auto, 0 - nnn)
Status	This column in the table shows the status of the LUN. Possible status can be None, Quick Formatted (and percentage completed), and Uncorrected.

Logical Units Tab Controls (back to top)

The Logical Units Tab contains the following that determine how the data is displayed or manipulated:

Feature	Description
	Click the to the left of the LUN name to select that LUN for deletion or to edit the cache pair for that LUN.
Rows/Page field	The tab can display from 25 to 1000 LUNs per page. Use the pull-down menu to the right of the Rows/Pages: field to set the number of LUNs to display per page.
Page field	This field displays the page number of the currently displayed page.
\|<	Moves display to first page
<	Moves display up one page
>	Moves display down one page
>\|	Moves display to last page

Displaying Detailed LUN Data (back to top)

To display detailed data about a specific LUN, double click the name of the LUN. The <LUN name> information window is displayed. See the help page for the LUN properties window for information about that window.

Displaying the Assigned Drives (back to top)

To display the list of drives assigned to the logical units in the selected RAID Group, select the Assigned Drives tab. The Assigned Drive tab is displayed. The list shows the logical unit name for each of the drives, the status of each drive, and the type of each listed drive.

To display the properties about a specific drive, double click the name of the drive. Navigator 2 displays the properties of the selected drive in a separate window.

Click Close to exit the drive window and return to the list of assigned drives.