CentOS 6.3 --- Building and installing DRBD from source (part 2)

Although we can simply install DRBD by using yum, maybe it is another choice to compile DRBD and kernel modules from source due to want to suit the kernel.
Update kernel
Display the current kernel release and hardware platform  by using “uname –r”by using “yum install kernel-devel” (# 1)
Update the kernel modules by “yum update kernel kernel-devel” next to reboot again.Now the kernel version is from “2.6.32-279.el6.x86_64” to “2.6.32-358.2.1.el6.x86_64”
Download and extract DRBD source
Due to wget command doesn’t exist in minimal installation, we have to install this utility by using “yum install wget”The console switch to /usr/src and begin to download DRBD source tarballs from LINBIT Open Source Software – drbd by using "wget http://oss.linbit.com/drbd/8.4/drbd-8.4.2.tar.gz "To uncompress DRBD into a directory /usr/src for keeping source code by using “tar zxvf drbd-8.4.2.tar.gz”
Check build prerequisiteInstall this utility for working C compiler by using “yum install gcc” (# 2)Install this utility for scanner(text pattern recongnizer)  generator by using “yum install flex” (# 3) Install this utility for building RPM (or rebuilding SPRM) package by using “yum install rpm-build” (# 4)Install this utility by using “yum install git” (# 5)Install this utility by using “yum install libxml2*” and “yum install libxslt*”  (# 6)

Install this utility by using “yum install make” (# 7)
Build RPM package
Switch to the source directory by using “cd drbd-8.4.2”To create the RPM building environment by running the command “mkdir -pv ~/rpmbuild/{BUILD,BUILDROOT,RPMS,SOURCES,SPECS,SRPMS}”To generate make files by using “./configure”by using “make rpm”by using “make km-rpm”
Install DRBD
Switch to a RPMS directory by using “cd ~/rpmbuild/RPMS/x86_64” and install drbd package by using “rpm –Uvh drbd-utils-….rpm drbd-km-….rpm”Load drbd module by using “modprob drbd” and verify whether drbd module is loaded by using "lsmod | grep drbd"
Reference :
(# 1) If no update kernel, RPM build will error when execute the command “make km-rpm”(# 2) If the system never install gcc package, we will get the following error when execute the command “./configure”(# 3) If the system never exist flex package, the checking process will fail when execute the command “./configure”(# 4) If the system never exist rpm-build package, the checking process will fail when execute the command “./configure”(# 5) If the system never exist git package, the checking process will fail when execute the command “./configure”(# 6) If the system never exist libxml2 and libxslt package, the checking process will fail when execute the command “./configure”(# 7) If the system never exist make package, the checking process will fail when execute the command “./configure”


<<< CentOS 6.3 --- Installing pre-built DRBD packages from distribution vendors (part 1)

CentOS 6.3 --- Installing pre-built DRBD packages from distribution vendors (part 1)

Due to DRBD has already merged into Linux 2.6.33 or above, we just only need to install the user land code if the Linux kernel is 2.6.33 or newer. That is the driver code in kernel and the user land code will recommend to use the same version as the kernel component. (# 1)

Due to the package DRBD does exist in the default yum repositories of RHEL 6/CentOS 6, we need to choose an extra package repository for installing DRBD by yum. In the moment, we will point to an extras RPM repository as ELRepo. (# 2)

At first, we have to realize O.S. name、version and information about current kernel by “cat /etc/redhat-release” & "uname -ri”. When understand the related information, we will begin to import the ELRepo public key by “rpm --import http://elrepo.org/RPM-GPG-KEY-elrepo.org”To install ELRepo for CentOS-6, we have to execute the command “rpm -Uvh http://elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm” (# 3)So does that we have already added a new yum repository “ELRepo” now.If we also want to use ELRepo mirror system and the package never is installed, we can execute the command “yum install yum-plugin-fastestmirror”
Maybe we prefer to keep some packages at the CentOS provided version so that we want to limit these packages don’t be updated by extra repository. For this reason, the package will not be automatically upgraded or installed by ELRepo repository.
To disable ELRepo repository, open the file “/etc/yum.repos.d/repo.repo” and change enabled parameter from 1 to 0
We can search DRBD packages via the command “yum --enablerepo=elrepo search drbd” to realize which version is in the ELRepo repository.To begin to install drbd via ELRepo by the command “yum --enablerepo=elrepo install –y drbd84-utils kmod-drbd84”
To view which version of DRBD file is installedTo know the DRBD kernel moduleTo realize which the version of the kernel module is installed
Of course, we have to install kernel module package and the related packages for the user land code if the Linux kernel is older than 2.6.33.
Reference :
(# 1) When we refer to the Linux releases with DRBD Official Web Site, we can know its relationship is between Linux releases and DRBD releases now.

Linux-release	DRBD-release
2.6.33	8.3.7
2.6.34	8.3.7
2.6.35	8.3.8
2.6.36	8.3.8.1
2.6.37	8.3.9
2.6.38	8.3.9
2.6.39	8.3.10
3.0 ~ 3.4	8.3.11
3.5 ~ 3.7	8.3.13
3.8	8.4.2

(# 2) ELRepo --- RPM repository for Enterprise Linux package
(# 3) If the CentOS host is behind the proxy server and want to use yum with a Proxy Server, we need to configure yum to go through proxy server.
         For a specific user with the default bash shell, we need to add some setting into the user’s shell profile ~/.bash_profile
         If the proxy server doesn’t require the authentication, we need to configure the profile settings as the following environment variable.
         If the proxy server require the authentication, we have to add the following variable including a username and password.
         For all users that connect to the proxy server, we can configure /etc/yum.conf to enable all yum operations to use a proxy server.