Question: How to Rebuild Grub on Linux servers with MSDOS Partition type. (proc) (hd0) (hd0,msdos5) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) 1. Execute the following commands in Grub prompt to set the root device and to load the boot image and initialize boot loader. > set root=(hd0,msdos1) > linux16 /vmlinuz-3.10.0-327.el7.x86_64 root=/dev/sda5 > initrd16 /initramfs-3.10.0-327.el7.x86_64.img Then boot the server. […]
OEL 7
How to configure EPEL repository in OEL 7
Question: How to install/get packages from EPEL Repository on OEL 7? 1. Create a repo file like /etc/yum/repos.d/epel-yum-ol7.repo. For example: # cat /etc/yum.repos.d/epel-yum-ol7.repo [ol7_epel] name=Oracle Linux $releasever EPEL ($basearch) baseurl=http://yum.oracle.com/repo/OracleLinux/OL7/developer_EPEL/$basearch/ gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle gpgcheck=1 enabled=1 2. And then run “yum repolist” command to see if repository is in there. # yum repolist Loaded plugins: langpacks repo id […]
How to install/get packages from Oracle EPEL Repository on OEL 7
Question: How to install/get packages from Oracle EPEL Repository on OL7? 1. Create a repo file like /etc/yum/repos.d/epel-yum-ol7.repo. For example: # cat /etc/yum.repos.d/epel-yum-ol7.repo [ol7_epel] name=Oracle Linux $releasever EPEL ($basearch) baseurl=http://yum.oracle.com/repo/OracleLinux/OL7/developer_EPEL/$basearch/ gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle gpgcheck=1 enabled=1 2. And then run “yum repolist” command to see if repository is in there. # yum repolist Loaded plugins: langpacks repo id […]
“yum clean all” not clearing yum repository cache in CentOS/RHEL/OEL
The Problem “Yum clean all” not clearing the yum cache information under /var/cache/yum for orcle Linux server which use Oracle public yum repository or local yum repository. # yum repolist Loaded plugins: refresh-packagekit, security, ulninfo public_ol6_UEK_latest | 1.2 kB 00:00 public_ol6_UEK_latest/primary | 26 MB 00:04 public_ol6_UEK_latest 554/554 public_ol6_latest | 1.4 kB 00:00 public_ol6_latest/primary | 58 […]
How To Enable PHP 7.0 And httpd24 On Oracle Linux 7
PHP7 is available and supported on OL7. The YUM distribution channel must be manually enabled for the RPM packages to be available: 1. Edit /etc/yum.repos.d/public-yum-ol7.repo file and make sure you enable “ol7_software_collections” repo. [ol7_software_collections] name=Software Collection Library release 3.0 packages for Oracle Linux 7 (x86_64) baseurl=https://yum.oracle.com/repo/OracleLinux/OL7/SoftwareCollections/x86_64/ gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle gpgcheck=1 enabled=1 2. Install PHP7.0 and http24: # […]
Understanding Ksplice Effective Kernel Version
This post will explain the meaning behind the output of the “ksplice kernel uname” (Ksplice Enhanced client) or “uptrack-uname” (Ksplice Uptrack client) command and how to interpret Ksplice’s effective kernel version string. The effective kernel version that is reported by Ksplice when running the command “ksplice kernel uname -r” reflects the security position of the […]
How to Check the Size of the Yum Channels in Oracle Linux
Question: How to find out how large a yum channel repository is, to know how much data the channel will sync to a local yum repository? To see the actual size of the repository use either the “yum repolist -v” or “yum repoinfo” command. 1. Example for checking the size of latest OL7 yum channel […]
How to Change Timezone from CST To EST in CentOS/RHEL 7 Server
Question: How to change timezone in CentOS/RHEL 7 server from EST to CST. Follow the below steps to change the timezone to CST. (Execute the below commands as root user) 1. List all the available timezones using the below command: # timedatectl list-timezones 2. Locate the correct timezone you need that is in the central […]
rm: cannot remove ‘doc/by-app’: Function not implemented (CentOS/RHEL 7)
The Problem Some user directories cannot be deleted. For example: /root/.cache/doc/ directory /root/.cache/doc/by-app directory If we try to delete the directory, we get the below error: # rm -rf /root/.cache/doc/ rm: cannot remove ‘doc/by-app’: Function not implemented The Solution The directories are the mount points for /dev/fuse device. # mount –mount (ext, ocfs2, nfs, gfs, […]
SSH Login Stuck At : “debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP” CentOS/RHEL 7
The Problem Trying to login via SSH, the session hangs. Adding “-vvv” option, shows that it hangs with below messages: debug1: expecting SSH2_MSG_KEX_ECDH_REPLY The Solution MTU was set to 9000 : # ip add| grep -i eth0 2: eth0: mtu 9000 qdisc pfifo_fast state UP group default qlen 1000 inet x.x.x.x/24 brd x.x.x.x scope global […]