In Linux, ensuring persistent device names for storage volumes is crucial, especially in environments where device names can change across reboots or when new devices are added. This persisting mapping become more crucial if you want to provision raw storage volume for Oracle ASM disks. There are two common methods to achieve this persistence either…
Category: RHEL-CentOS
How to clear memory cache and buffer in Linux
Linux, like other operating systems, has an efficient and affective memory management for managing memory hungry Application or database. RAM as you know is a vital part for Operating systems for storing code and data, in Linux it uses memory cache and buffer for improving the system performance. If I talk bit more about memory…
What are Ansible Host and Group Variables
Variables or Vars are used to store the data which is further used by ansible playbook. These variables can either take input from user or it can also be stored in YAML or INI file as well like main.yml or inventory. Variables stored in either playbook or in separate YAML or INI format file can…
How to mitigate Linux OpenSSH vulnerability CVE-2023-38408
The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if an agent is forwarded to an attacker-controlled system. (Code in /usr/lib is not necessarily safe for loading into ssh-agent.) NOTE: this issue exists because of an incomplete fix for CVE-2016-10009. Source Definition: CVE-2023-38408 at…
Enabling and Troubleshooting Hot Add Feature in Linux VMs
As a Linux System Admin, we have come across such requirement multiple times for Vertical scaling of Linux VMs in VMware infrastructure. Vertical scaling means adding of additional resources like CPU, memory, Storage to server or VM for increasing its capacity to address more load of Application or DB hosted on Linux VM but what…
How to manage the Apache logs with the help of Linux logrotation utility
Maintaining logs in busy Apache server is a very painful as frequent access of Apache webservice from clients can generate large size of logs example access_log and error_log which can consume the filesystem space but we should not stop generating these logs also as these logs are very helpful in troubleshooting the apache related issues…
RHEL 7 / CentOS 7 boot problem after P2V by using VMware converter
This issue is known issue with VMware converter 6.2.0 tool after P2V of either RHEL7 or CentOS7 Linux VM unable to boot and start throwing below error message in VM console Reason is P2V conversion put invalid character in grub configuration file along with command “: # (removed by Converter)” in front of grub parameters…
Understanding of Linux Inodes
Introduction to Inode File descriptors, file table and inode table in Linux. Image Source: Wikipedia An inode is a data structure on a filesystem on Linux and other Unix-likeoperating systems that stores all the information about a file except its name and its actual data. Inode is created during creation of file along with file…
How to recover or rebuild initramfs in CentOS 7 Linux
Corruption of initramfs can be occur by many ways for example after patching CentOS 7 Linux OS or installing a buggy device driver in server you found CentOS 7 Linux server has become unbootable. You may also encouter below kernel panic error because server initramfs got damaged . CentOS 7 Linux Kernel Panic screen Now…
How to Set password policy in CentOS or RHEL system
Linux is known for one of most secure Unix Operating System (OS) in world. But that is not mean it is 100% secure there is say in Information Technology (IT) no technology is a completely secure that is why from a System Administrator to CIO they take measure for securing IT infrastructure on regular basis…