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Introduction

An operating system (OS) on a Redundant Array of Independent Disks (RAID) volume is one of the high availability requirements of enterprise environments. Installing an OS on a RAID volume needs attention based on the kind of servers and RAID cards being used.

This article discusses the procedure to create RAID volumes before you install bare metal Linux OS on internal hardware RAID volumes. To deploy an OS on a hardware RAID volume, you must configure the hardware RAID before you install the OS. The procedure to configure hardware RAID volumes is described here.

In this example, the RAID configuration is performed on an IBM® Power® System S822LC (8001-22C) server having a 12 Gbps SAS3 RAID card that supports RAID 0, 1, and 10. Below are the details of the RAID card.

Prerequisites

You need to make sure that the following prerequisites are available:

  • USB flash drive
  • Facility to download the RAID utility
  • Access to the physical machine

Steps

Perform the following steps to configure the RAID volume:

  1. sas3ircu RAID utility is required for configuring RAID on EKEB card. This utility can be downloaded from the below location:
    ftp://ftp.supermicro.com/driver/P8DTU/.
    Download the utility in your notebook . Below is the direct link to the sas3ircu utility:
    ftp://ftp.supermicro.com/driver/P8DTU/LSI%20MegaRAID%20and%20HBA%20(AOC-Utility)/SMC-Broadcom%20(Supermicro%2012Gbs%20SAS%20HBA%20-%20AOC-S3008L-L8i)/AOC-S3008L-L8i/Tools//SMC-Broadcom%20(Supermicro%2012Gbs%20SAS%20HBA%20-%20AOC-S3008L-L8i)/AOC-S3008L-L8i/Tools/)

    Figure 1. sas3ircu utility download menu

  2. Attach the flash drive to your notebook.

  3. Copy the sas3ircu utility to the flash drive.

  4. Remove the flash drive from the notebook and attach it to one of the USB ports that is present in the rear side of the server.

    Figure 2. Rear view of the Power System S822LC server

  5. Boot the server to Petitboot by using the baseboard management controller (BMC) or Intelligent Platform Management Interface (IPMI) console. Refer https://www.ibm.com/support/knowledgecenter/en/linuxonibm/liabw/liabwkickoff.htm to configure IPMI/BMC IP and access Petitboot.

    Figure 3. Petitboot home menu

  6. Select Exit to shell to access the raid utility and create the RAID volumes.

    Figure 4. Petitboot Exit to shell option

  7. Change the directory to /var/petitboot/mnt/dev/.

  8. Run the ls -l command. The flash drive is seen as mounted on a directory. In this example, sdm1 is the flash drive. If no directory is visible, the flash drive is not mounted yet.

  9. Change the directory to the USB mount point sdm1. Run the ls -l command to verify that the sas3ircu utility is present.

    Figure 5. Petitboot shell command to access USB content

  10. Run the following command to list the RAID controllers. No output implies that no RAID card is available or not supported by the sas3ircu utility.
    #./sas3ircu list

    Figure 6. List RAID controllers using the sas3ircu utility

  11. Run the following command to list the disks that are associated with the controller. Note: You must use the controller index with the command. Here, the controller index is 0. Run the sas3ircu command. For example,
    # ./sas3ircu 0 display
    The following is the output (truncated) of the above command showing the details of controller with index 0

    Figure 7. RAID controller output of the sas3ircu utility

    Notes:
    Each disk is associated with an enclosure ID. In this example, the ID is 1.
    Each disk has a slot ID. Based on number of disks available in the enclosure, the slot IDs are numbered as 0, 1, 2 …N.
    A disk is identified with the Enclosure ID: Slot ID pair. For example, the first and the second disk are indicated as 1:0 and 1:1. The same notation is used with the sas3ircu utility.

  12. Identify the disks that must be under hardware RAID. These could be the disks to install the OS itself. After you identify the disks, complete the consecutive steps to create the RAID volumes. In this example, the RAID1 (Mirrored) volume is prepared to install the OS that has two underlying disks 1:0 and 1:1.

  13. Run the following command to create the RAID volume:
    #./sas3ircu 0 create RAID1 MAX 1:0 1:1 OSdisk
    Here is the syntax of the command:
    sas3ircu <<em>controller_#</em>> create sas3ircu <controller_#> create <volume_type> <size> {<Enclosure:Bay>}[VolumeName]
    Parameters
    <_controller_#_>: The index of the controller for the newly created volume.
    <_volume_type_>: Volume type for the new volume. Valid values are RAID 0, RAID 1, RAID 10, or RAID 1E.
    <_size_>: Size of the RAID volume in MB, or MAX for the maximum size available.
    <_enclosure: bay_=””>: The Enclosure: Bay value of the disk drive for the new RAID volume.
    [VolumeName]: A user-specified string to identify the volume. This is optional.

  14. Run the following command to verify that the RAID volume is created:
    #./sas3ircu 0 display
    The following is a truncated output that is displayed when you run this command. This shows that the name of the new volume created is OSdisk and it contains disks in slot numbers 1:0 and 1:1.

    Figure 8. RAID volume output of the sas3ircu utility

  15. The RAID build process takes time based on the size of the disks. You can view the RAID build status by running the following command:
    #./sas3ircu 0 status

  16. Repeat step 13 to create any additional RAID volumes on free disks. Substitute free disk details before running the command.

  17. After creating the RAID volumes, complete the procedure to install the Linux OS on the RAID volume. See https://www.ibm.com/support/knowledgecenter/en/linuxonibm/liabw/liabwkickoff.htm for more information.
    Note: The installers detect the RAID volumes as regular disks.

Conclusion

In this article, you learnt how to create RAID volumes before you install the Linux OS on a bare metal IBM® Power® System S822LC system.