ASM

The post describes the process about how to setup ASM & ASMLIB disks using Mapper Multipath disks. The process involves : Installing and configuring the ASMLIB software Creating partitions on multipath devices using kpartx Creating ASM disks on new partitions updating the configuration file /etc/sysconfig/oracleasm Creating ASM disk groups 1. Install and configure ASMLIB software Install the ASMLIB (on each node for RAC environments) and configure it. ASMLib consists of the … [Read more...] about How to install and configure Oracle ASMLIB on Native Linux multipath mapper devices

Question : The asmcmd command execution is slow. How to trace the asmcmd command? Answer: You are seeing some errors or slow performance issue with command execution on asmcmd. And you wish to get more information on the command execution. The exception raised from asmcmd is not very descriptive and more of generic errors are reported for different issues. Below are some of the ways in which you can trace the asmcmd command to troubleshoot the performance issues with the execution of the … [Read more...] about How to trace asmcmd command on UNIX/Linux

Question : A datafile was wrongly added on file system instead of ASM diskgroup. How to move it to the ASM disk group again? Answer : 1) Make sure the datafile to be moved is OFFLINE before proceeding : SQL> alter system switch logfile; System altered. SQL> select file_name, file_id from dba_data_files; FILE_NAME FILE_ID --------------------- /u01/oracle/oradata/test1.dbf 6 SQL> alter database datafile 6 offline; Database altered. SQL> select file_name, file_id, online_status from … [Read more...] about How to Move a Datafile from Filesystem to ASM Using ASMCMD CP Command

ASMLIB is a support library for the Automatic Storage Management (ASM) feature of the Oracle Database and is available for the Linux operating system. When ASMLIB is used to manage ASM disks, the device path information is not presented in GV$ASM_DISK.PATH. This post shows how to get the physical disk device name associated with the ASMLIB disk name. Finding asmlib disk name and asm disk name By default when you scan disks with oracleasm scandisks, the corresponding disk device files (ASMLIB … [Read more...] about Oracle ASM : Shell script to map physical disk devices to ASMLIB disks

Error: Oracleasm create disk failure on RHEL 7 with following error. # oracleasm createdisk DATA1 /dev/sde1 Writing disk header: done Instantiating disk: failed Clearing disk header: done Solution When disk is created with verbose option (-v) you would see : # oracleasm createdisk -v DATA1 /dev/sde1 Disk "DATA1" does not exist or is not instantiated Writing disk header: done Instantiating disk: oracleasm-instantiate-disk: Unable to open manager: No such file or … [Read more...] about CentOS / RHEL 7 : Oracleasm Create Disk Failed “Instantiating disk: failed”

Moving a datafile from the file system can be achieved in two ways. 1. While the database is shutdown (in mount stage). 2. While the database is running (with the selected tablespace offline). While the database is shutdown (in mount stage) Moving oracle datafile while the database is in mount stage is performed in the following way: 1. Shutdown and mount the database. $ sqlplus '/as sysdba' SQL> shutdown immediate; SQL> startup mount; 2. Ensure you have enough space in the ASM … [Read more...] about How to move a datafile from file system to ASM

In the event you cannot mount your ASM disk groups, you will be unable to start any databases using those disk groups. Here is a possible error reported when mounting ASM disk groups: SQL> startup mount ORA-15032: not all alterations performed ORA-15063: diskgroup "[DISK GROUP NAME]"" lacks quorum of 2 PST disks; 0 found This error may occur if: a) ASM disk(s) is not visible on the operating system. b) asm_diskstring parameter is not set correctly on ASM instance(s) c) ASM metadata … [Read more...] about How to recreate an ASM disk group