Red Hat Enterprise Linux 5 Administration Unleashed

OS Core Concepts Troubleshooting 553OS Core Concepts TroubleshootingQ. I am trying to create a directory named data in my home directory, but every time Iexecute the mkdir /data command, I receive the error message Permission denied.Why am I not allowed to create a new directory?A. If you are trying to create a directory in your home directory from the command line,be sure the current working directory is your home directory, and then execute thecommand mkdir data, without the slash (/) in front of data. The slash in front of thedirectory name means that you are providing the full path to the directory, and youdon’t have permission to create a directory on the top level of the filesystem.Q. I want to update the RPM package for the Apache web server, but I have customizedthe configuration file already. If I update the package, will I lose my customizedconfiguration file?A. No. If you have a modified configuration file when updating the RPM that providesit, one of two actions occurs. If the default configuration file in the updated packagehasn’t changed between the package version you have installed and the version ofthe updated package, the configuration file is left alone because it still works withthe updated package version.If the configuration file has changed in the updated package version, the existingconfiguration file is renamed with a .rpmsave extension such as httpd.conf.rpmsave, and the new configuration file from the updated package is saved to thefilesystem. If this occurs, the modifications must be redone in the new configurationfile, but the old configuration file can be referenced because it is not lost.Q. I need to remove some packages from my Red Hat Enterprise Linux server because theyare not needed for the function of the server. Can I just use the rpm -e command to remove them or do I need to use the Yum utility to remove them?A. You can use either the rpm or the yum command to delete the packages from thesystem, but using Yum has one major advantage. If the package being removed isrequired to be installed by other packages, the rpm command displays an errormessage listing the packages that require the one trying to be removed, and thepackage is not removed. Yum can provide this same list and also ask whether youwant the additional packages removed at the same time. You can review the list ofadditional packages and decide whether it is safe to remove them as well.DQ. I modified the /etc/modprobe.conf file to change the kernel module used for thenetwork card in my system. After rebooting to enable the changes, how do I verifythat the different module is being used?A. The lsmod command lists all the kernel modules currently loaded. Use thecommand lsmod | grep , where is the name of thenew module to use. If the command outputs a line containing information aboutthe module, it has been loaded.