C H A P T E R  6

Logical Drives

This chapter explains how to create and manage logical drives using the "view and edit Logical drives" menu option.



Note - Procedures that have already been described in other chapters are cross-referenced instead of repeated.



Topics covered include:


Viewing the Logical Drive Status Table

To check and configure logical drives, choose "view and edit Logical drives" from the Main Menu. For a description of the parameters, see Logical Drive Status Table.


Viewing Physical Drives

Use this option to view all physical drives that make up a selected logical drive and to view the status of those physical drives.


procedure icon  To View Physical Drives

1. From the Main Menu, choose "view and edit Logical drives."

The logical drive status table lists all logical drives that have been configured on the array.

2. Select a logical drive.

A menu of logical drive options is displayed.

 Screen capture showing a logical drive (LG) selected with the Logical menu displayed. View scsi drives is chosen.

3. Choose "View scsi drives" to display all physical drives that make up the logical drive and to view the status of each physical drive.


Creating Logical Drives

See Creating Logical Drives for the procedure for creating logical drives on a SCSI array.

See Creating Logical Drives for the procedure for creating logical drives on FC and SATA arrays.

See Deleting Logical Drives for the procedure for deleting logical drives on SCSI arrays.


Deleting a Logical Drive

See Deleting Logical Drives for the procedure for deleting logical drives on FC and SATA arrays.

See Deleting Logical Drives for the procedure for deleting logical drives on a SCSI arrays.



caution icon

Caution - This operation erases all data on the logical drive. Therefore, if any data exists on the logical drive, copy it to another location or back it up before it is deleted.




Partitioning a Logical Drive

See Partitions for a description of logical drive partitions and a procedure for partitioning a logical drive on a SCSI array. See Partitions for a description of logical drive partitions and a procedure for an FC or SATA array.


Deleting a Logical Drive Partition

When you delete a partition on a logical drive, all of the capacity of the deleted partition is added to the remaining partition with the highest partition number. For example, if a logical drive contains partitions 0 through 3 and you delete partition 3, all of the capacity of partition 3 is added to partition 2.


procedure icon  To Delete a Logical Drive Partition

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive that has a partition you want to delete.

3. Choose "Partition logical drive."

Partitions of the logical drive are displayed in a table.

4. Select the partition you want to delete.

5. Type 0 to delete this partition.

 Screen capture showing a partition of a logical drive with Partition Size (MB) configured with 0.

A warning prompt is displayed:

This operation will result in the LOSS OF ALL DATA on the partition.

Partition Logical Drive?


As illustrated in FIGURE 6-1, the capacity of the deleted partition 1 (200 MB) is added into the partition above the deleted partition (partition 0), which combines 100 MB and 200 MB for a total of 300 MB.

  FIGURE 6-1 Example of Deleted Partitions

The figure shows the capacity added to partition 2 after partition 1 has been deleted.


caution icon

Caution - If a partition has been changed, you must reconfigure all host LUN mappings. All the host LUN mappings are removed with any partition change.




Changing a Logical Drive Name

See To Assign a Logical Drive Name (Optional) for the procedure for assigning a name to a logical drive on a SCSI array. See To Assign a Logical Drive Name (Optional) for the procedure for assigning a name to a logical drive on a FC or SATA array.


Rebuilding a Logical Drive

If no spare drive is available for logical drive rebuilding, replace the failed drive immediately with a new drive and initiate the rebuild process manually.

For more information about manually and automatically rebuilding logical drives, see Rebuilding Logical Drives.


procedure icon  To Rebuild a Logical Drive

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive that has a failed member drive.

3. Choose "Rebuild logical drive," and then choose Yes to rebuild the logical drive.



Note - The "Rebuild logical drive" option only displays when the selected logical drive (with RAID level 1, 3, or 5) includes a failed physical drive (Status DRV FAILED). NRAID and RAID 0 configurations provide no data redundancy.



Screen capture showing failed member drive selected and "Rebuild Logical Drive?" prompt.

The rebuilding progress is displayed on the screen.

 Screen capture showing Rebuild progress bar with 73% completed displayed.

When rebuilding has already started or the logical drive has been automatically rebuilt by a local spare drive or global spare drive, choose "Rebuild progress" to view the rebuilding progress. To cancel a rebuild operation, choose "Abort rebuild."

A notification message informs you when the process is complete.

Rebuild of Logical Drive x Completed.



Changing a Logical Drive Controller Assignment

See To Change a Controller Assignment (Optional) for the procedure for changing a logical drive controller assignment on the SCSI array. See To Assign a Logical Drive Name (Optional) for the procedure for changing a logical drive controller assignment on the FC array or SATA array.


Expanding the Capacity of a Logical Drive

Use this option to expand the capacity of an existing logical drive. For example, you might originally have had several 18-Gbyte physical drives, of which only 9 Gbyte each were selected to build a logical drive. To use the remaining 9 Gbyte in each physical drive, you need to expand the logical drive. After a logical drive is expanded, the total additional capacity is displayed as a new partition. The new partition must be mapped to a host LUN in order for an HBA to recognize it. RAID levels 0, 1, 3, and 5 support expansion.



Note - To expand a logical volume, you must first expand the logical drives that make up the logical volume.




procedure icon  To Expand a Logical Drive

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive you want to expand.

3. Delete any local spare drives assigned to this logical drive.

It is not necessary to delete any global spare drives. See Deleting a Spare Drive for more information about how to delete a local spare drive.

4. Choose "Expand logical drive."

A menu displays the following options:

Choose this option to determine how much of the available capacity to add to the logical drive.

Choose this option to expand the logical drive on-line or off-line.

Choose this option to use the logical drive before initialization is complete. Because the controller is building the logical drive while performing I/O operations, initializing a logical drive on-line requires more time than off-line initialization.

Choose this option to use the drive only after initialization is complete. Because the controller is building the logical drive without having to also perform I/O operations, off-line initialization requires less time than on-line initialization.

5. Choose "Drive Expand Capacity."

The maximum available drive free capacity information is displayed.



Note - The free capacity shown refers to the maximum available free capacity per physical drive, based on the smallest physical drive in the logical drive.



 Screen capture shows the Maximum Available Drive Free Capacity and Maximum Drive Expand Capacity configured to the same value (14476 MB).

6. Press Return to expand the logical drive using all available capacity, or enter a value up to the maximum drive expand capacity.

The capacity shown in the Maximum Available Drive Free Capacity field is the maximum available free disk space per physical drive, based on the smallest physical drive in the logical drive. The capacity you specify is added to each physical drive in the logical drive.

As described in the following examples, the total amount of capacity that is added to the logical drive is automatically calculated based on the RAID level.

If you know the total maximum drive capacity by which you want to expand a logical drive, perform the following calculations based on the RAID level to determine the amount to enter in the Maximum Drive Expand Capacity field:



Note - The Maximum Drive Expand Capacity cannot exceed the Maximum Available Drive Free Capacity.



7. (Optional) If you want to expand the logical drive offline instead of the default online mode, choose "Initialize mode," and then choose Yes to confirm your choice.

You can repeat Step 7 if you want to change logical drive expansion back on to on-line.

See Creating Logical Drives

8. When the logical drive capacity and initialize mode are selected, press Escape, and then choose Yes to expand the logical drive.

A notification message informs you when the process is complete:

On-Line Expansion of Logical Drive 0 Completed


9. Press Escape to return to the previous screen.

Drive capacity information is displayed. The total capacity of the logical drive has been expanded to 68952 Gbyte.

 Screen capture showing that the logical drive capacity has been expanded to 68952 Gigabytes.

10. Map the new partition:

11. (Solaris operating system only) For the Solaris operating system to recognize a LUN, you must first manually write the label using the Auto configure option of the format (1M) utility.

For the SCSI array, see To Label a LUN. For the FC array or SATA array, see To Label a LUN.


Adding Physical Drives

When you add a physical drive to a logical drive, the capacity of the original logical drive remains the same and additional capacity is displayed as a new partition. For example, if you have a single 200-Gbyte logical drive and add a 36-Gbyte drive, the total logical drive is 236 Gbyte with two partitions (one 200-Gbyte partition and one 36-Gbyte partition). The new partition must be mapped to a host LUN for the HBA to recognize it.

Physical drives can be added to RAID 0, 1, 3, and 5 logical drives. For RAID 1 configurations, physical drives must be added in pairs.

The operation of adding physical drives cannot be canceled once it has started. If a power failure occurs, the add operation pauses. When the power comes back on, the controller automatically continues the operation

If a physical drive in a logical drive fails during the add operation, the add operation pauses and resumes automatically after a logical drive rebuild has completed.


procedure icon  To Add a Physical Drive to a Logical Drive

1. From the Main Menu, choose "view and edit logical drive."

2. Select a logical drive.



Note - For logical drives configured as RAID 1, you must add physical drives in pairs.



3. Choose "add Scsi drives" to display a list of available drives.

4. Select one or more drives to add to the target logical drive.

The physical drive you choose should have a capacity no less than the original physical drive. If possible, use drives of the same capacity. All drives in the array are treated as though they have the capacity of the smallest physical drive in the logical drive. The selected drive is indicated by an asterisk (*) mark.

 Screen capture shows the first submenu shows an available drive selected, the second submenu shows the selected drive indicated by an asterisk (*) mark.

5. Press Escape when all physical drives have been selected, and then choose Yes to add the drives.

A notification is displayed.

 Screen capture showing the "Adding Notification" message.

6. Press Escape to display a status bar that indicates the percentage of progress.

 Screen capture showing the progress bar.

A notification message informs you when the process is complete.

Add SCSI Drive to Logical Drive 0 Complete


When the add operation is completed, data is re-striped across the original and newly added drives.

7. Map the partition:

8. (Solaris operating system only) For the Solaris operating system to recognize a LUN, you must first manually write the label using the Auto configure option of the format (1M) utility.

For the SCSI array, see To Label a LUN. For the FC array or SATA array, see To Label a LUN.


Performing a Parity Check

For RAID 3 and RAID 5 configurations, the primary purpose of the parity checking operation is to ensure that all sectors of the media can be successfully read and to provide alerts if a drive is starting to experience read or write errors.

A RAID 3 and RAID 5 parity checking operation recalculates the parity of data stripes in each of the logical drive's RAID stripe sets and compares it with the stored parity. Depending on which options are enabled, if a discrepancy is found, an error is reported and the new correct parity is substituted for the stored parity. For RAID 1 configurations, if an inconsistency is encountered, data is copied from the master disk to the slave disk. If a bad block is encountered when parity is regenerated, data is copied from the other disk, master or slave, to the reporting disk drive reallocating the bad block.

You can check the integrity of your data before overwriting the parity drive. In this case you can manually regenerate the parity after you have reloaded the data from backup. See Manually Regenerating the Parity of a Logical Drive for more information. Or you can enable the "Overwrite Inconsistent Parity" menu option, which causes the RAID controller to correct the data on the parity drive automatically whenever a parity check detects an inconsistency as explained in Overwriting Inconsistent Parity. To specify whether to report inconsistent parity errors as system events, see Generating a Check Parity Error Event.

Manually Regenerating the Parity of a Logical Drive

If you have disabled the "Overwrite Inconsistent Parity" menu option, the controller reports any inconsistency found in a parity check without overwriting the parity drive, which enables you to check your data and determine if it is intact or if the error occurred on a data drive. Once you've made this determination, and reloaded the data from backup if necessary, you can manually regenerate the parity using the "reGenerate parity" menu option.


procedure icon  To Regenerate the Parity of a Logical Drive

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive that you want to regenerate the parity on.

3. Choose "reGenerate parity right arrow Execute Regenerate Logical Drive Parity," and then choose Yes to regenerate parity.

A notification is displayed that parity regeneration has begun.

4. Press Escape to view the progress indicator.



Note - If a regenerating parity process is stopped by a drive failure, the process cannot restart until the logical drive rebuild has been completed.



Overwriting Inconsistent Parity

Enabling the "Overwrite Inconsistent Parity" menu option causes the RAID controller to correct the data on the parity drive automatically whenever a parity check detects an inconsistency. In most cases, it is important to correct the data on the parity drive as soon as an inconsistency is detected to avoid the potential for data loss in the event of a drive failure.

However, you might prefer to check the integrity of your data before overwriting the parity drive. Disabling the "Overwrite Inconsistent Parity" menu option causes the controller to report any inconsistency found in a parity check without overwriting the parity drive. In this case, you can check your data and determine if it is intact or if the error occurred on a data drive. Once you've made this determination, and reloaded the data from backup if necessary, you can manually regenerate the parity using the "reGenerate parity" menu option.



caution icon

Caution - Restoring data by automatically overwriting the original data might cause data loss. To enable you to check your data and determine if it is intact or if the error occurred on a data drive, disable the "Overwrite Inconsistent parity" menu option.




procedure icon  To Enable or Disable Overwrite Inconsistent Parity

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive whose automatic parity area overwriting you want to enable or disable.

The default value is Enabled.

3. To toggle between enabling and disabling this menu option, choose "reGenerate parity right arrow Overwrite Inconsistent Parity -," and then choose Yes to confirm the change.

4. Choose "Regenerate Logical Drive Parity," and then choose Yes to regenerate parity.

Generating a Check Parity Error Event

When a parity check is performed, you can specify whether to report inconsistent parity errors as system events.


procedure icon  To Enable or Disable Reporting Inconsistent Parity Errors as System Events

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive whose inconsistent parity you want to enable or disable as a system event.

The default value is Enabled.

3. To toggle between enabling and disabling this menu option, choose "reGenerate parity right arrow Generate Check Parity Error Event -," and then choose Yes to confirm the change.


Clearing a Fatal Fail Logical Drive Condition

With a RAID array system, your system is protected with the RAID parity drive and a global spare or spares. A FATAL FAIL condition occurs when more drives fail than your RAID redundancy can accommodate. The redundancy of your RAID array depends on your configuration. In a RAID 3 or RAID 5 configuration, two or more drives must fail for a FATAL FAIL status. In a RAID 1 configuration, you can lose multiple drives without fatal failure if all the failed drives reside on one side of a mirrored pair.

It is sometimes possible to recover the RAID array from a FATAL FAIL. For the detailed procedure to use, refer to the "Recovering From Fatal Drive Failure" section in the "Troubleshooting Your Array" chapter of the Sun StorEdge 3000 Family Installation, Operation, and Service Manual for Sun StorEdge 3510 FC and 3511 SATA Arrays.

The Fatal Fail condition remains after the drive problem is fixed and the controller is reset. A "Clear state" menu option enables you to wait until you are sure the drive problem has been corrected before clearing the Fatal Fail logical drive condition and rebuilding the logical drive, if necessary.

1. From the controller firmware's Main Menu, choose "view and edit Logical drives."

2. Select the logical drive with the FATAL FAIL status and press Enter.

3. Select "Clear state."

4. Choose Yes when the "Back to degraded?" or "Back to normal?" prompt is displayed.

After clearing the FATAL FAIL, the status changes to DRV FAILED.


Copying and Replacing Drives With Drives of Larger Capacity

For logical drives configured for RAID levels 0, 3, and 5, you can copy and replace existing physical drives with drives of the same or higher capacity. Because the logical drive uses the capacity size of its smallest size, all drives must be replaced with drives of the same or higher capacity. For example, as shown in FIGURE 6-2, a logical drive that originally contains three 36-Gbyte physical drives can be replaced with three new 73-Gbyte physical drives.



Note - To use the additional capacity provided by drives with higher capacity, you must expand the capacity as explained in To Expand a Logical Drive.



  FIGURE 6-2 Expansion by Copy and Replace

Figure illustrating the logical drives being expanded by replacing all of the member drives with drives of a higher capacity.

Additional capacity is displayed as a new partition. The new partition must be mapped to a host LUN for the HBA to recognize it.


procedure icon  To Copy and Replace a Drive

1. From the Main Menu, choose "view and edit Logical drives."

2. Select a target logical drive.

3. Choose "cOpy and replace drive."

The physical drives belonging to the selected logical drive are listed.

4. Select the member drive (the source drive) that you want to replace with a larger drive.

A table of available physical drives is displayed.

5. Select a new drive onto which you will copy the content of the source drive.

The channel number and ID number of both the source drive and the destination drive are displayed in a confirmation message.

 Screen capture showing the member drive (the source drive) to be replaced and the destination drive (the replacing drive).

Choose Yes to confirm.

6. A notification message is displayed.

LG:0 Logical Drive NOTICE:CHL:2 ID:6 Starting Clone


7. Press Escape to view the progress.

 Screen capture showing the progress bar.

A notification message informs you when the process is complete.

LG:0 Logical Drive NOTICE:CHL:2 ID:6 Copy and Replace Completed


8. Repeat these steps to copy and replace all member drives with drives of higher capacity as needed.

You can now choose "Expand logical drive" to make use of the capacity brought by the new drives and then map the additional capacity to a host LUN.

 Screen capture showing the "Drive Copying Notification" message.


Scanning Drives for Bad Blocks

The media scan feature sequentially checks each physical drive in a selected logical drive, block by block, for bad blocks. If a bad block is encountered, the controller rebuilds the data from the bad block onto a good block if one is available on the physical drive. If no good blocks are available on the physical drive, the controller designates the physical drive BAD and generates an event message. If a spare drive is available, the controller begins rebuilding data from the bad physical drive onto the spare.

You can specify whether media scanning begins automatically whenever the controller is powered up or reset. SeeMedia Scan at Power-Up for more information.

See Using Media Scan on Individual Drives for more information about performing media scans on individual drives.

By default, assigned global spares are not scanned, nor are unassigned drives.

Whenever media scan is running on a drive, its front-panel LED flashes green.

You can change the priority of a particular media scan operation to specify the frequency of drive scanning.


procedure icon  To Terminate a Media Scan

1. From the Main Menu, choose "view and edit Logical drives."

2. Select the logical drive that is currently being scanned.

3. Choose "Media Scan right arrow Abort Media Scan," and then choose Yes to terminate the media scan.


procedure icon  To Perform a Media Scan

1. From the Main Menu, choose "view and edit Logical drives."

2. Select a logical drive.

3. Choose "Media scan" to display a menu of media scan options.

4. (Optional) You can determine the priority of media scanning as related to other CPU tasks.

a. Choose "Media Scan Priority."

The Media Scan Priority menu is displayed.

Media scan is not performed until other tasks have been completed.

Media scan is typically performed within three seconds.

Media scan is typically performed within one second.

Media scan is performed immediately.

b. Select a priority.

5. (Optional) Configure the media scan iteration count to specify whether the physical drives that make up the selected logical drive are checked one time or continuously, by choosing "Iteration Count -" and then choosing Yes to confirm the change.

6. When media scan is satisfactorily configured, press Escape, and then choose Yes to begin the media scan.

The front-panel LEDs for the drives being scanned will blink until the media scan is terminated.

LG:x NOTICE: CHL:x ID:x Starting Media Scan


Shutting Down a Logical Drive

Use the "Shutdown logical drive" menu option to:


procedure icon  To Shut Down a Logical Drive

1. From the Main Menu, choose "view and edit Logical drive" to display a list of logical drives in the Logical Drive Status table.

2. Select the logical drive that you want to shut down.

3. Choose "sHutdown logical drive," and then choose Yes to shut down the logical drive.

The Status column of the Logical Drive Status window changes to SHUTDOWN.

 Screen capture showing the Logical Drive Status table with the status of logical drive S1 changed to SHUTDOWN.

4. Reset the array controller ("system Functions right arrow Reset Controller") to restore the logical drive to an online state (GOOD status).


Changing Write Policy for a Logical Drive

The global write policy for all logical drives is configured to write-back cache (default) or write-through cache as described in Enabling and Disabling Write-Back Cache. You can configure a different write policy for individual logical drives using the "Write policy" menu option. A logical drive's write policy can be changed at any time.


procedure icon  To Configure a Logical Drive's Write Policy

1. From the Main Menu, choose "view and edit Logical drive" to display a list of logical drives in the Logical Drive Status table.

2. Select the logical drive that you want to configure.

3. Choose "Write policy -."

The following write policy options are displayed:

This menu option assigns the global write policy to the selected logical drive. If the global setting for write policy is changed, automatically changes the write policy for this logical drive.

As described in Cache Write Policy Guidelines, the array can be configured to dynamically switch write policy from write-back cache to write-through cache if specified events occur. Write policy is only automatically switched for logical drives with write policy configured to Default. See Event Trigger Operations for more information.

This menu option assigns write-back cache regardless of any changes to the global write policy.

This menu option assigns write-through cache regardless of any changes to the global write policy.

 Screen capture showing the displayed Write Policy options.

4. Choose a write policy option

 Screen capture showing displayed Write Policy options with "Write-Back" selected.

The logical drive's write policy is changed.