Adding data LUNs to SAN File System

This topic describes how to add data LUNs to SAN File System.

Prerequisites

Attention: For non-disruptive addition and expansion of volumes, the client operating systems must support on-line replacement and on-line insertion (OLR/OLI) capability. If the clients do not have OLI/OLR capability, then the clients will not be able to discover the newly added LUNS without disruption. In this case, you must reboot the client machines to discover the LUNs.

Context

This task describes how to add data LUNs without having to stop the cluster, stop and restart each metadata server, and start the cluster.

Steps

  1. Assign the host bus adapters (HBAs) of the new storage systems (for example, IBM® Enterprise Storage System (ESS)) to the appropriate zones, as required.
  2. Setup LUN masking for the newly added LUNs by mapping the new LUNs to the metadata server engines according to LUN restrictions, limitations, and considerations for mapping.
  3. Perform online insertion (OLI) of the LUNs on each Linux™ client machine:
    1. Force the HBA driver to rescan the fabric. For example, if you are using the QLogic driver, enter these commands at the system prompt:
      echo scsi-qlascan >/proc/scsi/qla2300/2
      echo scsi-qlascan >/proc/scsi/qla2300/3
    2. View the target ID and the LUN for all LUNs that were added by entering the following command at the system prompt:
      more /proc/scsi/qla2300/2
    3. Record the ID LUN combination for any LUN that is not yet registered with the operating system.
    4. For each controller number (2 and 3 are the controller numbers for the QLogic 2342 ports) and ID LUN combination, enter this command at the system prompt:
      echo "scsi add-single-device controller 0 ID LUN">/proc/scsi/scsi
    5. Force the Subsystem Device Driver (SDD), or equivalent driver, to rescan and map the new devices. For SDD, enter the following command at the system prompt:
      /usr/sbin/cfgvpath
  4. Perform online insertion (OLI) of the LUNs on each Solaris client machine:
    1. Run the HBA utilities to perform online LUN insertion (OLI) of the newly added LUNs. Refer to your HBA documentation for more information.
    2. The Solaris client automatically detects new data LUNs. If the client does not detect a new LUN, run the devfsadm –c disks command to manually force the operating system to scan for new LUNs.
  5. The AIX® and Windows® clients automatically detect new data LUNs so no additional steps are required for those clients.
  6. Rediscover existing and new LUNs and add the new LUNs to SAN File System’s list of LUNs using the rediscoverluns -client command from the administrative CLI. Issue this command for each client machine.
  7. Verify that all clients can access the new LUNs using the reportclient -lun command from the administrative CLI.

Parent topic: Managing volumes and LUNs

Related reference
rediscoverluns
reportclient

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