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5 Replies Latest reply: Feb 28, 2013 12:37 PM by Dude! RSS


993838 Newbie
Currently Being Moderated
Hi, everyone I am new to Oracle Linux. I've been having problems with OEL5.8x64 sg module, when attempting to start it. It comes back with FATAL:Module sg not found. This all came about when I was trying to start the hostagent(Unisphere). Thinking it was a PowerPath compatibility issue, I reinstalled the OS without any EMC apps. Ran the modprobe command, like clock work FATAL: Module sg not found. Has anyone here been able to resolve this? Any help would greatly appreciated, thank you in advance.

  • 1. Re: OEL SG FATAL
    Dude! Guru
    Currently Being Moderated
    Are you using the UEK kernel?

    The SG driver should be built-in and not a module. You can check the following:
    # cat /boot/config-`uname -r` | grep CONFIG_CHR_DEV_SG
    # cat /proc/scsi/sg/version 
    30534     3.5.34 [20061027]
    Perhaps you are missing the sg3-utils package and therefore what you are trying to install fails.
    yum install sg3-utils
  • 2. Re: OEL SG FATAL
    993838 Newbie
    Currently Being Moderated
    Hi Dude, thanks for your reply. Yes that's what I've read and I have read your post on another post too. It does show that sg3_utils-1.25-5.el5x86_64 installed. I pretty much selected all the sg updates via UNL. With that said, shouldn't I be able to run modprobe without the FATAL error?


    Your old post:
    About SG (Scsi Generic) module on OEL6
  • 3. Re: OEL SG FATAL
    alvaromiranda Explorer
    Currently Being Moderated
    as a workaround if your software require the module

    you can boot into kernel-normal do the install and switch to kernel-uek

    the software must be hardcoded to find the module based on /lib/modules/$(uname -r)/

    [oracle@ol5 ~]$ find /lib/modules/ -name sg*

    [oracle@ol5 ~]$ uname -a
    Linux ol5.kikitux.lan 2.6.32-300.39.4.el5uek #1 SMP Tue Feb 5 23:20:24 PST 2013 i686 i686 i386 GNU/Linux
    [oracle@ol5 ~]$
  • 4. Re: OEL SG FATAL
    993838 Newbie
    Currently Being Moderated
    Alvaro, thanks for the reply. Not really sure what's going on the with kernel 2.6.(above 18). SG.ko is just not there. This is my kernel version.


    I downloaded CentOS5.8 kernel-2.6.18-308.el5, sg.ko and everything installed/started properly. I will do as you instructed in another post to obtain the OEL5.8 kernel-2.6.18-308.el5. Thank you everyone.
  • 5. Re: OEL SG FATAL
    Dude! Guru
    Currently Being Moderated
    There is no need to install anything from CentOS under OL. Just follow the instructions at and use yum to install the kernel you need. For instance:

    # yum list kernel kernel-uek
    Installed Packages
    kernel.x86_64 2.6.18-274.el5
    kernel.x86_64 2.6.18-308.el5
    kernel-uek.x86_64 2.6.32-200.13.1.el5uek
    kernel-uek.x86_64 2.6.32-300.10.1.el5uek

    Check the following output:

    # find /lib/modules -iname sg.ko

    # grep CONFIG_CHR_DEV_SG /boot/config-2.6.18-274*

    # grep CONFIG_CHR_DEV_SG /boot/config*uek

    The above shows that the RHEL kernel supplies the sg driver as a module, while the UEK kernel has the driver built-in. What you are trying to install seems to check for the kernel module, which is probably silly. What are you trying to install? Anyway, Oracle Linux supplies the UEK and RHEL kernel and you can choose which one to use.


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