The Ask While Installing the 12c Grid Infrastructure (GI) with the intention of having 3 copies of voting disks and OCR files, we created +GRID diskgroup with 3 underlying luns. However, because we chose "external redundancy" for the diskgroup ended up having just one copy of voting disk and OCR files with no option of multiplexing them in the same group. The Solution Before we get into the solution to this ask, lets first see what exactly is "external", "normal" and "high" … [Read more...] about How to move ASM spfile from External Redundancy To Normal Redundancy in version 12.1.0.2 and above
How to install git on ubuntu 16.04
This small howto post covers the installation and configuration of Git client on your ubuntu 16.04. We will install git version 2.9.3 that comes with a large number of updates versus previous release 2.8. Git is a version control system that is used for software development and other version control tasks. This post assumes you have at least basic knowledge of Linux, know basic shell command for Linux. The installation is quite simple and assumes you are running in the root account, if not … [Read more...] about How to install git on ubuntu 16.04
SSSD: How to disable PREAUTH permanently in CentOS/RHEL 7
The Ask If file /var/lib/sss/pubconf/pam_preauth_available is present then SSSD will initiate PREAUTH unless below is set in PAM module. auth sufficient pam_sss.so use_first_pass Even when file /var/lib/sss/pubconf/pam_preauth_available is deleted, it is recreated during next SSSD service restart. How to disable PREAUTH permanently in CentOS/RHEL 7? The Solution To disable PREAUTH permanently, follow the steps given below. 1. Login to the server as root. 2. Take backup … [Read more...] about SSSD: How to disable PREAUTH permanently in CentOS/RHEL 7
Order of environment calls for different OS shells in Linux
Knowing the order of execution of the environment variables for different OS Shell(s) is very important for a system administrator. This might be useful for setting up cron jobs or for understanding differences in commands run in an interactive shell vs batch jobs using a non-interactive shell. 1. Shell: CSH Startup (order): --> .cshrc (always) --> .login (login shells) Termination: --> .logout (login shells) Others: .history (saves history based on "$savehist") 2. Shell: … [Read more...] about Order of environment calls for different OS shells in Linux
SSSD Service Failing with “SSSD is already running” in CentOS/RHEL 7
The Problem User is unable to start sssd service and can see following errors in the log files. # tailf /var/log/messages ... Jan 26 12:48:54 xxx systemd: Starting System Security Services Daemon... Jan 26 12:48:54 xxx sssd: SSSD is already running Jan 26 12:48:54 xxx systemd: sssd.service: main process exited, code=exited, status=2/INVALIDARGUMENT Jan 26 12:48:54 xxx systemd: Failed to start System Security Services Daemon. Jan 26 12:48:54 xxx systemd: Unit sssd.service entered failed … [Read more...] about SSSD Service Failing with “SSSD is already running” in CentOS/RHEL 7
How To Disable Advanced Analytics in Oracle Database 12c?
The Ask The Advanced Analytics is eanbled on the oracle database 12c as shown below. SQL> select * from v$option where PARAMETER like '%Advanced Analytics%'; PARAMETER VALUE CON_ID ---------------------------------------- -------------------- ---------- Advanced Analytics TRUE 0 User wants to disable this option from database. The Solution In Oracle 12c, Oracle Advanced Analytics is a combination of … [Read more...] about How To Disable Advanced Analytics in Oracle Database 12c?
“Bad id for repo: My Repo, byte = 2” yum update error
The Problem While executing yum commands user is getting below error: # yum update Bad id for repo: My Repo, byte = 2 The following is the repo file which is used for local dvd image # cat /etc/yum.repos.d/my_repo.repo [My Repo] name=repo1 baseurl=file:///mnt/iso/ enabled=1 gpgcheck=0 The Solution [My Repo] is wrong as it uses spaces between letters which are not properly translated by yum. Do not include white space in [My Repo]. So to correct it change the name file from … [Read more...] about “Bad id for repo: My Repo, byte = 2” yum update error
How to disable lvmetad in CentOS/RHEL
What is lvmetad LVM can optionally use a central metadata cache, implemented through a daemon (lvmetad) and a udev rule. The metadata daemon has two main purposes: it improves the performance of LVM commands and it allows udev to automatically activate logical volumes or entire volume groups as they become available to the system. How to disable lvmetad You may sometime experience that LVM changes are not reflected by the rest of the nodes in your cluster. After creating a volume group on a … [Read more...] about How to disable lvmetad in CentOS/RHEL
How to disable rtkit-daemon in CentOS/RHEL
As per package description, RealtimeKit is a D-Bus system service that changes the scheduling policy of user processes/threads to SCHED_RR (i.e. real-time scheduling mode) on request. It is intended to be used as a secure mechanism to allow real-time scheduling to be used by normal user processes. Command "rpm -q --whatrequires rtkit" will list all the rpm packages installed on the system which requires rtkit. # rpm -q --whatrequires rtkit pulseaudio-10.0-5.el7.x86_64 If there is no … [Read more...] about How to disable rtkit-daemon in CentOS/RHEL
How to configure rsysnc in daemon mode (allow rsync and disable SSH login) in CentOS/RHEL
The Ask The customer wants to disable SSH login and only enable rsync to transfer data. The Solution It is possible to allow rsync and disable ssh by configuring rsync in daemon mode. In order to achieve this below steps can be performed. 1. Configure rsync in daemon mode in server. For this we need to first modify file /etc/rsyncd.conf, the following is an example: # vi /etc/rsyncd.conf motd file = /etc/rsyncd.motd log file = /var/log/rsyncd.log pid file = /var/run/rsyncd.pid lock … [Read more...] about How to configure rsysnc in daemon mode (allow rsync and disable SSH login) in CentOS/RHEL