Dhiraj Kumar's Blog

Category: oracle

  • ASM Disk Migration Error: Sector Size Mismatch Between RHEL 7 and RHEL 8 ([512] vs [4096])

    Environment Details: We are migrating a standalone Oracle Restart-based database server from RHEL 7 to RHEL 8. The existing ASM disks were created using ASMLib 2 on RHEL 7. Post-migration steps included: Mounting the NetApp LUNs (created in RHEL 7) onto the new RHEL 8 (or RHEL 9) server. Running the following commands: All above…

  • Introduce GRUB As The Most Commonly used Bootloader In Linux.

    GRUB is a bootloader used in most Linux distributions. A bootloader is a small program responsible for loading the operating system into memory and starting it. GRUB supports multiple operating systems, making it an excellent tool for dual-boot setups. There are two main versions of GRUB: GRUB 2 offers better support for modern filesystems, modularity,…

  • Storage AFD:UNMAP Protocol With ASM Disk

    In Oracle storage environments using ASM (Automatic Storage Management) with AFD (ASM Filter Driver), the UNMAP protocol plays a key role in space reclamation—especially when you’re using thin-provisioned storage such as SSDs or SAN systems that support SCSI UNMAP or NVMe deallocation. What is the UNMAP Protocol? The UNMAP protocol is a SCSI command (or…

  • Installing ASM Library Version 3.1 (ASMLib V 3.1) for Oracle 19c on Linux 8.3 or later in aarch64

    ASM Library (ASMLib) is a support library for the Oracle Automatic Storage Management (ASM) feature. It simplifies storage management and enhances Oracle ASM functionality. Prerequisites Required Packages In this demonstration, I installed the ASMlib V3 package on Oracle Linux 8.9 with the aarch64 architecture. Therefore, you need to download the package that matches your Linux…

  • Getting ORA-02097 and ORA-15014 On Setting asmcmd dsset ‘AFD:*’ In Oracle RAC

    I was attempting to migrate Oracle ASM UDEV-managed disks to Oracle ASM Filter Driver (AFD). Although I followed all the documented steps for migrating the disks, I encountered the following error when trying to set the disk strings: This error occurred specifically during the step where I attempted to configure the ASM disk discovery string.…

  • OPatchAuto Bootstrapping Failure with Error Code 255 and Resource Temporarily Unavailable

    OPatchAuto execution fails during the bootstrap phase with error code 255.The failure prevents successful patching operations. Symptom Getting issue while running the Opatchauto on my Oracle Restart Envioment: Cause Based on the analysis, it came to know that on my system bash ,zip package was not installed Also perl was not found on the location…

  • Multiple Database Services Are Not Constant Across the Scan Listeners In Two Nodes RAC

    In a Real Application Cluster (RAC) setup, the SCAN listener running on Node 1 was able to register only the local instances, but failed to register remote instances from other nodes. In contrast, the SCAN listener on Node 2 functioned as expected and was able to register instances from both Node 1 and Node 2.…