10.4 Scanning for Devices

If you add more disks to the SAN, you can use the rescan-scsi-bus.sh script to scan for the new devices without rebooting. For information, see Scanning for New Devices without Rebooting in the SLES 11 SP4: Storage Administration Guide.

You can also use the following procedure to scan the devices and make them available without rebooting the system:

  1. On the storage subsystem, use the vendor’s tools to allocate the devices and update its access control settings to allow the Linux system access to the new storage. Refer to the vendor's documentation for details.

  2. On the Linux system, use the HBA driver commands to scan the SAN to discover the new devices. The exact commands depend on the driver.

    For example, for a QLogic 2300 HBA, the command is

    echo scsi-qlascan >/proc/scsi/qla2xxx/<host number>

    At this point, the newly added device is not known to the higher layers of the Linux kernel's SCSI subsystem and is not yet usable.

  3. Scan all targets for a host to make its new device known to the middle layer of the Linux kernel's SCSI subsystem. At a terminal console prompt, enter

    echo "- - -" >/sys/class/scsi_host/host<hostnumber>/scan

  4. If the devices have multiple paths, run the Multipath tool to recognize the devices for Device Mapper Multipath I/O (DM-MPIO) configuration. At a terminal console prompt, enter 

    multipath

    For information about configuring multipathing for devices on your Linux server, see Managing Multipath I/O for Devices in the SLES 11: Storage Administration Guide.

10.4.1 Scanning for Devices using iManager

The system typically recognizes all devices on reboot or after you create them. If you add devices to a server and the system does not automatically detect them, you might need to scan for devices.

IMPORTANT:This feature is available only for servers of version OES 11 or later.

  1. In iManager, click Storage > Scan for Devices.

  2. Select a server to manage.

    The browser displays the Scan Devices page.

    IMPORTANT:After iManager connects to the server, it scans for devices and displays them in the Devices list. The scan can take several seconds, depending on the number of adapters and disks on your systems. Click Cancel at any time to back out of the process.

  3. View the list of devices.

    NOTE:You can only view the list. There are no actions to make from this page.