Manage RAID volumes

The appliance employs a Redundant Array of Independent Drives (RAID) level system to ensure that if a drive fails it can be hot swapped without having to power down the appliance, thus providing a high degree of reliability in the case of single disk failure. This topic describes how to check the RAID status, and how to swap a faulty disk.

Check the RAID status

You can check the status of the RAID volumes on the RAID Status page. Information about the RAID array is displayed in a table on the RAID Array Status page. The following table shows an example of the RAID status from a live appliance:

List of Virtual Disks in the System
Controller PERC 6/i Integrated (Embedded)
ID : 0
Status : Ok
Name : Virtual Disk 0
State : Ready
Progress : Not Applicable
Layout : RAID-1
Size : 136.13 GB (146163105792 bytes)
Device Name : /dev/sda
Type : SAS
Read Policy : No Read Ahead
Write Policy : Write Back
Cache Policy : Not Applicable
Stripe Element Size : 64 KB
Disk Cache Policy : Disabled
List of Physical Disks on Controller PERC 6/i Integrated (Embedded)
Controller PERC 6/i Integrated (Embedded)
ID : 0:0:0
Status : Ok
Name : Physical Disk 0:0:0
State : Online
Failure Predicted : No
Progress : Not Applicable
Type : SAS
Capacity : 136.13 GB (146163105792 bytes)
Used RAID Disk Space : 136.13 GB (146163105792 bytes)
Available RAID Disk Space : 0.00 GB (0 bytes)
Hot Spare : No
Vendor ID : DELL(tm)
Product ID : ST9146803SS
Revision : FS03
Serial No. : 3SD0FPZX
Negotiated Speed : Not Available
Capable Speed : Not Available
Manufacture Day : 06
Manufacture Week : 20
Manufacture Year : 2009
SAS Address : 5000C50012E55CBD
ID : 0:0:1
Status : Ok
Name : Physical Disk 0:0:1
State : Online
Failure Predicted : No
Progress : Not Applicable
Type : SAS
Capacity : 136.13 GB (146163105792 bytes)
Used RAID Disk Space : 136.13 GB (146163105792 bytes)
Available RAID Disk Space : 0.00 GB (0 bytes)
Hot Spare : No
Vendor ID : DELL(tm)
Product ID : ST9146803SS
Revision : FS03
Serial No. : 3SD0FAE0
Negotiated Speed : Not Available
Capable Speed : Not Available
Manufacture Day : 06
Manufacture Week : 20
Manufacture Year : 2009
SAS Address : 5000C50012E5CC09

The first section of this data, titled List of Virtual Disks in the System, refers to the virtual disk. This is the storage interface used by the appliance, and is accessible from the /dev/sda device node. The State of the virtual disk is Ready. If a component of the array is missing or faulty the State would be Degraded.

The remaining sections, which are listed under the List of Physical Disks on Controller heading, refer to the physical disks that comprise the virtual disk. In this case, there are two physical disks, which are online and operating normally as shown by the Status and State fields (OK and Online respectively).

Swap a faulty disk

If the Status of a physical disk is not Ok, open an SSH session to the appliance (using the credentials configured using the Web Administration Interface), and complete the following steps to resolve the problem:

  1. Determine which physical drive is faulty. The faulty drive can usually be identified by observing the front panel of the drive. If the top LED is blinking regularly and turns from green to amber on one of the drives, this is the faulty one.
  2. Otherwise, if the LED is not blinking and you need to physically identify the faulty drive on the appliance, you can manually force the faulty drive to blink (for example, if the 0.0.0 drive has been reported as faulty in the RAID status output above). You can then force the 0.0.0 drive to blink so you can identify it on the appliance by issuing the following command:
  3. Appliance:~# omconfig storage pdisk action=blink controller=0 pdisk=0:0:0
  4. Substitute the actual Physical Disk ID of the faulty disk for 0:0:0 in the above example.
  5. If the drive is not already offline, issue the following command to set it offline:
  6. Appliance:~# omconfig storage pdisk action=offline controller=0pdisk=0:0:0
  7. Replace the faulty drive with a compatible and properly functioning disk drive.
  8. When the new drive has been added to the virtual RAID drive, the RAID Array Status page displays the progress as follows:
  9. List of Virtual Disks in the System
    Controller PERC 6/i Integrated (Embedded)
    ID : 0
    Status : Non-Critical
    Name : Virtual Disk 0
    State : Degraded
    Progress : Not Applicable
    Layout : RAID-1
    Size : 136.13 GB (146163105792 bytes)
    Device Name : /dev/sda
    Type : SAS
    Read Policy : No Read Ahead
    Write Policy : Write Back
    Cache Policy : Not Applicable
    Stripe Element Size : 64 KB
    Disk Cache Policy : Disabled
    List of Physical Disks on Controller PERC 6/i Integrated (Embedded)
    Controller PERC 6/i Integrated (Embedded)
    ID : 0:0:0
    Status : Ok
    Name : Physical Disk 0:0:0
    State : Rebuilding
    Failure Predicted : No
    Progress : 2% complete
    Type : SAS
    Capacity : 136.13 GB (146163105792 bytes)
    Used RAID Disk Space : 136.13 GB (146163105792 bytes)
    Available RAID Disk Space : 0.00 GB (0 bytes)
    Hot Spare : No
    Vendor ID : DELL(tm)
    Product ID : ST9146803SS
    Revision : FS03
    Serial No. : 3SD0FPZX
    Negotiated Speed : Not Available
    Capable Speed : Not Available
    Manufacture Day : 06
    Manufacture Week : 20
    Manufacture Year : 2009
    SAS Address : 5000C50012E55CBD
    ID : 0:0:1
    Status : Ok
    Name : Physical Disk 0:0:1
    State : Online
    Failure Predicted : No
    Progress : Not Applicable
    Type : SAS
    Capacity : 136.13 GB (146163105792 bytes)
    Used RAID Disk Space : 136.13 GB (146163105792 bytes)
    Available RAID Disk Space : 0.00 GB (0 bytes)
    Hot Spare : No
    Vendor ID : DELL(tm)
    Product ID : ST9146803SS
    Revision : FS03
    Serial No. : 3SD0FAE0
    Negotiated Speed : Not Available
    Capable Speed : Not Available
    Manufacture Day : 06
    Manufacture Week : 20
    Manufacture Year : 2009
    SAS Address : 5000C50012E5CC09

You can see from the Progress field that the new disk has completed 2% of the rebuilding process. When this process is complete the drive automatically becomes part of the RAID array and the RAID Array Status page should look like the original status page above.

For more detailed instructions on configuring RAID arrays, see the Dell PowerEdge Owner's Manual, available from the Dell Support website.

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