CentOS/RHEL 6

The Problem CentOS/RHEL 6 system reboot due too out of memory error: DUMPFILE: vmcore [PARTIAL DUMP] CPUS: 2 DATE: Mon Feb 29 05:28:02 2016 UPTIME: 33 days, 09:45:55 LOAD AVERAGE: 1.88, 1.52, 1.41 TASKS: 218 NODENAME: localhost RELEASE: 2.6.32-431.el6.x86_64 VERSION: #1 SMP Sun Nov 10 22:19:54 EST 2013 MACHINE: x86_64 (3000 Mhz) MEMORY: 8 GB PANIC: "Kernel panic - not syncing: Out of memory: system-wide panic_on_oom is enabled" PID: 31010 COMMAND: "java" … [Read more...] about CentOS/RHEL 6 Kernel Panic – “Out of memory” kernel parameter panic_on_oom is enabled

1. In CentOS/RHEL core file creation is disabled by default. To enable it, executing the below command: # ulimit -S -c unlimited > /dev/null 2>&1 then execute the program in the same shell environment. 2. To enable it permanently, please follow steps below: - Edit /etc/security/limits.conf. # vi /etc/security/limits.conf * soft core unlimited The '*' is used to enable coredump size to unlimited to all users. - Edit /etc/sysctl.conf to add the path of the core dump and file … [Read more...] about How to enable core dump for Applications on CentOS/RHEL

Question: How to add additional language support in CentOS/RHEL? To add specific language support in CentOS/RHEL, you need firstly confirm the correct language group name by "yum grouplist" command. # yum grouplist The available language groups will be displayed in yum output as below: # yum grouplist Loaded plugins: refresh-packagekit, rhnplugin Setting up Group Process Installed Groups: ... Installed Language Groups: Arabic Support [ar] Armenian Support [hy] ... Available … [Read more...] about How to add additional language support in CentOS/RHEL

This post explains how to analyse the segfault message in message file and to identify the problem in application or operating system side. What is "segfault"? A segmentation fault (often shortened to segfault) or access violation is a fault raised by hardware with memory protection, to notify operating system (OS) about a memory access violation. The Linux kernel will response it by performing some corrective action, generally passing the fault to the offending process by sending the … [Read more...] about What are “segfault” messages in /var/log/messages file

The Problem rpm commands issue the following error: rpm: error while loading shared libraries: /usr/lib64/liblzma.so.0: invalid ELF header The Solution In this instance, either liblzma.so or the link to it (/usr/lib64/liblzma.so.0) had gotten overwritten. $ rpm -qa | grep binutils rpm: error while loading shared libraries: /usr/lib64/liblzma.so.0: invalid ELF header To resolve this issue, the liblzma.so file and associated soft link need to be restored. Follow the steps outlined below … [Read more...] about rpm: error while loading shared libraries: invalid ELF header

The Problem When trying to delete volume group by using lvremove, vgremove, pvremove command after executing shred command for physical volume as shown below, fails repeatedly. # shred -vfz -n 3 /dev/sdd # sum -r /dev/sdd 28911 1073741824 When the lvremove command is executed, you will get an error saying that the volume group can not be found. # lvremove /dev/VolGroupOracleArch/lvol0 Volume group "VolGroupOracleArch" not found Cannot process volume group VolGroupOracleArch The … [Read more...] about lvremove failing to remove volume after using ‘shred’ command

This post briefly outlines how it possible to re-create the yum cache, or said in another way, force a fetch of the cache data from the enabled yum repositories. The enabled yum repositories are the ones in the following file /etc/yum.conf or in the following folder /etc/yum.repos.d that have their "enabled" setting to "1", e.g. : # vi /etc/yum.repos.d/test.repo [test_repo] name=Test … [Read more...] about How to re-create the yum cache (force a fetch of the cache data) from enabled repositories in CentOS/RHEL

1. Create a directory for you local repository, e.g. /home/mypackage_dir/repository. Move the RPMs into that directory. # mkdir /home/mypackage_dir/repository # cp /media/packages/* /home/mypackage_dir/repo 2. Fix some ownership and filesystem permissions: # chown -R root:root /home/mypackage_dir/repo 3. Install the createrepo package if not installed yet, and run: # createrepo /home/mypackage_dir/repo # chmod -R o-w+r /home/mypackage_dir/repo 4. Create a repository configuration … [Read more...] about How to Create yum Repository in CentOS/RHEL