Apps DBA Workshop

In this blogpost we will see how we can use the GFS2 (Global File System 2) on Oracle Linux 9 allows multiple cluster nodes to concurrently access a shared block storage device—ideal for highly available applications in a clustered environment (e.g., with KVM, OLVM, or Pacemaker clusters). Prerequisites: System Requirements Oracle Linux 9 with UEK kernel Shared block storage (iSCSI, FC, or shared disk) 1. Cluster infrastructure (Pacemaker/Corosync) Fencing configured (GFS2 requires it) Install Required Packages (on all nodes): bash#dnf install -y gfs2-utils lvm2-cluster pcs fence-agents-all 2. Enable and Start Cluster Services: bash#systemctl enable --now pcsd bash#echo "yourpassword" | passwd --stdin hacluster bash#pcs host auth node1 node2 node3 -u hacluster -p yourpassword bash#pcs cluster setup --name gfscluster node1 node2 node3 bash#pcs cluster start --all bash#pcs cluster enable --all 3. Configure Shared Storage: If using LVM, make sure to enable cluster...

In one of our customer Environments we cloned virtual machine using the disk and post clone completion virtual machine not booted up. The following Error occurred while booting up the VM. [ TIME ] Timed out waiting for device /dev/mapper/vg_rootdisk-volume. [DEPEND] Dependency failed for /filesystem [DEPEND] Dependency failed for D-Bus System Message Bus. Problem: File /etc/lvm/devices/system.devices configured with the disk_id of the OLVM disk image. If the VM is cloned the new VM will be on a new image with a different disk_id and that will prevent LVM from finding the logical volumes and hence its not able to boot the VM. Solution: Eidt /etc/lvm/devices/system.devices configuration file before creating the clone or copy. Change from IDTYPE=sys_serial and IDNAME= : # LVM uses devices listed in this file. # Created by LVM command lvmdevices pid 3503 at Jan 13 23:11:07 2024 VERSION=1.1.4 IDTYPE=sys_serial IDNAME=ad1a270f-10e9-41dc-a313-988d07e6b447 DEVNAME=/dev/sda2 PVID=...

 In this blogpost you will learn how quickly we can install postgresql on Oracle Linux 9 Server.  Check the package of PostgreSQL using the dnf command: Installation of PostgreSQL package: - Setup the postgreSQL Database: - Start and Enable the postgreSQL Service: - Check the status of the postgreSQL Service The postgreSQL started, enabled and working fine without any issues.  Hope it helps  !! Thanks for reading. regards, Zaheer

In this blogpost we will see how we can change the hostname on Oracle Linux 9 Operating System.  We can change hostname on Oracle Linux 9 using the simple "hostnamectl" command without restarting any services and it will be reflected immediately on the host. Check the current hostname: Set new hostname: The hostname has been changed from Linux9 to Linux10 using one simple command. Thanks for reading :)  regards, Zaheer