Disabling lvm2-lvmetad.socket/service on CentOS/RHEL 7 system works while the system is running, but after a reboot, it comes up again. This post will show you how to prevent this from happening. 1. Modify the /etc/lvm/lvm.conf file with your favorite file editor, like vi or nano, and switch the value of “use_lvmetad = ” from 1 […]
Archives for May 2019
How To Change A Dictionary Managed Tablespace To A Locally Managed Tablespace
Question: How to migrate Dictionary Managed Tablespace (DMT) to a Locally Managed Tablespace (LMT) using DBMS_SPACE_ADMIN.TABLESPACE_MIGRATE_TO_LOCAL procedure? Warning: It is highly recommended to test the steps in similar test environment to have an estimate of the time required for migration before implementing in Production. You can use the DBMS_SPACE_ADMIN.TABLESPACE_MIGRATE_TO_LOCAL procedure to migrate a tablespace from […]
How to install/remove/query/update RPM packages in Linux (Cheat Sheet)
Maintaining Software Using RPM (Red Hat Package Manager) RPM is a powerful software manager which can be used to build, install, query, verify, update, and uninstall individual software packages. An RPM package consists of an archive of files, and package information such as name, version, a description and information about dependencies on other RPM packages. […]
Extend the size of /boot partition on virtualized environment (CentOS/RHEL 6)
The scope of this post is to explain the steps involved in increasing the /boot filesystem, when no sufficient space available to install new kernel package. Though we have standard methods to reduce the size of /boot i.e. removing unused kernel and image files from boot, as an alternate approach, this post illustrate the steps […]
How To Disable Ksplice Service on OEL
This post will assist you to disable ksplice service or when ULN registration time enabled this service unknowingly. 1. Login to URL with ULN credentials https://status-ksplice.oracle.com/status/ -> Allow/Deny Policies -> Select your hostname > then choose all or deny. Once denied, cannot do operations with uptrack or ksplice. For example: [root@client ~]# uptrack-upgrade -n This […]
Volume “test_vg/lvol0” is not active locally – Error while running lvcreate
The Problem While trying to create a logical volume, lvcreate fails with error “Volume “test_vg/lvol0″ Is Not Active Locally” even though the volume group is active, with an error output such as the following: # lvcreate -L 4G test_vg Volume “test_vg/lvol0” is not active locally. Aborting. Failed to wipe start of new LV. The Root […]
Command ntpstat Shows unsynchronised (CentOS/RHEL)
The ntpstat command output shows “unsynchronised”: # ntpstat unsynchronised time server re-starting The “ntpq -p ” command output shows none of ntp servers is chosen: # ntpq -p ========================================== remote refid st t when poll reach delay offset jitter =============================================== ntp-server .INIT. 16 u – 16 0 0.000 0.000 0.000 ntp-server .INIT. 16 u – […]
How To Check Swap Usage of Each Processes in Linux
This post shows how to check swap usage of each process, answering “How can I know what process would consume the largest swap space?” For all kernels Swap usage is shown as “Swap” columns in /proc/[PID]/smaps. This indicates swapped memory size of the each memory ranges, thus the sum of all of these values shows […]
How to Check Swap Usage Live via the ‘top’ Command in Linux
Question: How to view the system-wide swap usage on a CentOS/RHEL server via the top command to identify the highest consumers. Below are the steps for CentOS/RHEL 5 and 6 which are the same, followed by CentOS/RHEL 7 as they differ on this release: NOTE: Performing this task will not cause any changes to top […]
Unable To Boot Up Linux OS with Auditd (CentOS/RHEL)
The Problem A Linux OS failed bootup, from console log we can see all goes well in the very beginning, kernel loaded and init scripts were running OK. But suddenly the Linux OS was shutting down (received TERM signal) after auditd daemon started. … dracut: Switching root mount: mount point /proc/bus/usb does not exist Welcome […]