I have installed Oracle Enterpise Linux 6 but "sg" module was not loaded default by OS."FATAL: Module sg not found." error is printed when i try to "modprobe sg" command.
SG module is loaded default on Redhat 6 but as far as i see it does not install default on OEL 6.Secure Backup and EMC storage HostAgent software need to SG module on Linux.
Which package(s) should be selected during the OEL6 minimal installation ? or how can i install sg module on OEL 6 after minimal installation ?
If you help me,I will be happy.
Hi,thanks for your reply.
You can see the below information about OS and sg version.
# uname -r
# cat /etc/oracle-release
Oracle Linux Server release 6.1
# cat /proc/scsi/sg/version
30534 3.5.34 
Are the devices for the QLogic Fibre Channel Host Bus Adapters really named sg using a generic scsi driver?
You might also want to check if you have kernel-uek-firmware installed. I don't recall the exact kernel version, but some later versions of 2.6 separate the drivers and firmware. Pls check you dmesg output.
# yum install kernel-uek-firmware
Btw, from what I read, no Oracle database products are certified for OL 6 yet. Unless this is for experimental purpose, I'd stick to OL 5U7 until further notice.
I have checked with rpm -qa | grep -i kernel and saw the kernel-uek-firmware-2.6.32-100.34.1.el6uek.noarch package so kernel-uek-firmware has already installed.
Ok,if OL6 is not certified yet for Oracle product,I will try to install OL5U7 and check the sg module.But still i can not understand,why OL6 does not use sg module while RHEL6 can use.
Do you have offical URL address for which OS is certified by Oracle poduct ?
Is this the correct version for your current uek-kernel (uname -r)?
Perhaps the RHEL kernel does not have a driver installed for your HBA adapter and is therefore using a generic driver. You might want check what special devices the qla2xxx driver actually creates, which may not be /dev/sg*.
You could also check the lspci -v output using the RHEL kernel and compare it with the UEK kernel to see what driver your kernel is using for the HBA adapter.
What do you see in "cat /proc/scsi/scsi"?
What does the following output:
find /lib/modules -name sg.ko
If the SG module is missing in the uek directory tree, which is probably the case, then the question will be if this is intended, a bug or whether the "old" sg device is obsolete with the newer uek kernel.
What about the installation of Secure Backup and EMC stuff? Is it meant to work for the uek-kernel version? Is there any newer software required by the vendor?
Thanks for reply.Our find command output like below.
# find /lib/modules -name sg.ko
Secure backup need to sg module.You can see in below address
On EMC side,I am getting to error "Error:sg module was not loaded" when i try to start EMC HostAgent service.EMC HostAgent is a Linux Agent for comminicate to EMC storage correctly via fiber channel.Actually,EMC HostAgent is support OL4 and OL5.I am using newer version for Secure Backup and EMC HostAgent.
I tried to install OL5U7 on same server and "sg" module not load by default.I will try to install OL5.5 As far as i know OL5.5 is certified by Oracle Products.I think,this will be the best choice.
I've checked the kernel-uek source tree (http://public-yum.oracle.com/repo/OracleLinux/OL6/1/base/x86_64/kernel-uek-2.6.32-100.34.1.el6uek.src.rpm) and there seems to be no sg module, but there is /usr/src/kernels/2.6.32-100.34.1.el6uek.x86_64/include/scsi/sg.h, which actually contains some interesting information. I could be wrong, but perhaps the sg driver is build into the kernel and not a module.
Regarding Oracle Secure Backup, I vaguely remember from Integration of RMAN with virtual tape library it requires to install the sg3_utils and sg3_devel packages.
Did you install them? You might want to try if this makes any difference.
# yum install sg3_utils sg3_utils-devel
You can use the above command following the repo setup instructions at http://public-yum.oracle.com
Other than that, perhaps there are udev rules in/lib/udev/rules.d/ that affect the SG devices.