Linux how to

Practical instructions on how to go about doing things in Linux. This is about the Fedora Linux.

How to extend an xfs filesystem

• xfs filesystems must be mounted to be extended. There is no need to unmount
• usually an xfs fileystem occupies all of its logical volume so the extension of a filesytem involves first the expansion of the logical volume and then the extension of the filesystem

• expanding the logical volume

• lvextend -L +5G /dev/Volume00/data-lv00 - this will add 5GB on logical voluem /dev/Volume00/data-lv00
• xfs_growfs /NewFS - this will extend the filesystems on the previously extended LV to occupy it completely. The filesystem is mounted on /NewFS in this case.

More on how to operate the Logical Volume Manager (LVM) is found here

How to extend an ext3 file system

Note: A mounted ext3 file system cannot be extended. Unmount it before proceeding.

• Unmount the file system
• expand the logical volume containing the file system

• lvextend -L +2G /dev/Volume00/lvol00 - this will add 2GB on logical volume /dev/Volume00/lvol00

• do an fsck on the file system (this is required)

• e2fsck /dev/Volume00/lvol00

• extend the filesystem to the logical volume limits

• resize2fs /dev/Volume00/lvol00

• remount file system

How to install java

• 1. Download the latest JDK version from Sun. Choose the "Linux self-extracting file" version (not the RPM version).
• 2. Make sure the "rpm-build" package is installed:

 yum install rpm-build

• 3. Move the JDK to the RPM Building Source directory:

 mv jdk-* /usr/src/redhat/SOURCES/

• 4. Download the Source RPM from JPackage. Make sure you choose the same version as the JDK you downloaded in step 1.
• 5. Build the Java RPM using the file that you just downloaded:

 rpmbuild --rebuild java-*src.rpm

• 6. After the build the RPMs can be found in /usr/src/redhat/RPMS/i586/. You can install them using yum:

 yum -y localinstall /usr/src/redhat/RPMS/i586/java-1.5.0-sun-*

• 7. If you want to enable the Java plugin for your web browser do the following:

 ln -s $JAVA_HOME/jre/plugin/i386/ns7/libjavaplugin_oji.so /usr/lib/mozilla/plugins/

• 8. Make sure that the old X11 libraries are installed, or Java will crash your web browser:

 yum install xorg-x11-deprecated-libs