Linux – multiple LUNs

SCSI devices support multiple LUNs

Platform:RHEL AS 3 QU3    Kernel:2.4.29
Download last kernel from  web sit. (RHEL misses some of source code)

  1. Enter X-Windows mode and open a new terminal
    #cd /usr/src/linux-2.4/
    #vi Makefile
    # make clean
    # make mrproper
    # cp /boot/config-2.4.20-20.ELsmp .config
    # make oldconfig (If you don’t know what these new features do .Just say “No”)
    # make xconfig

    (1) Enter “Processor type and features”
    Set processor family for suitable processor.
    (2) Enter “File system”
    Set “EXT3 joumalling file system support to  “Y”
    (3) Enter “SCSI support/Some SCSI devices(eg.CD jukebox) support multiple LUNs”
    Set ”Probe all LUNs on each SCSI device   to  “Y”
    (4) Save and Exit

  2. make dep clean bzImage modules modules_install install
    # make dep
  3. /sbin/lilo (If used LILO as boot load)

    Make modules(eg:qla2300.o)

    ln -s /usr/src/linux-2.4.29 /usr/src/linux2.4

    Download qlogic module from  web sit.

    # tar zxvf qla2x00-version.tgz
    # cd qlogic
    # /drvrsetup
    # depmod –a
    # modprobe qla2300

    You can have more than 1 LUN in Linux system.

    There is a easy way to support multi-LUNs under RHEL 3 .(No recompile kernel necessary,RHEL 3 doesn’t support multi-LUNs by default kernel)

    When using storage configured with Logical Unit Number(LUNs)greater than zero,it is necessary to enable LUN support by adding the following to /etc/modules.conf

    # vi /etc/modules.conf
    Options scsi_mod max_scsi_luns=255

    After modifying modules.conf, it is necessary to rebuild the initial ram disk using mkinitrd.