To set up Oracle Automatic Storage Management (ASM), you need to follow certain steps. Here's a brief overview of the process:
- Install Oracle Grid Infrastructure: ASM is a component of Oracle Grid Infrastructure, so start by installing Grid Infrastructure on the servers where ASM will be configured.
- Configure Grid Infrastructure: Use the Oracle Universal Installer to configure Grid Infrastructure. This involves specifying the installation directory, Oracle base, and inventory locations.
- Create a separate disk group for ASM: Determine the disks that you want to allocate for ASM storage and create a disk group. This can be done using the ASM Configuration Assistant (ASMCA) or command-line tools like SQL*Plus or ASM Configuration Assistant (ASMCA).
- Configure ASM: Configure ASM by setting up initialization parameters. These parameters define the behavior of ASM, such as the disk group redundancy level, rebalancing preferences, and performance-related settings.
- Mount the disk group: Once the ASM configuration is complete, mount the disk group using the ALTER DISKGROUP...MOUNT command. This makes the disk group available for use by Oracle databases.
- Create or migrate databases to ASM: Create new databases or migrate existing ones to use ASM for storage. This involves specifying the disk group as the storage location for database files (data files, control files, redo logs, etc.) during the database creation or migration process.
- Manage ASM: After setting up ASM, you need to manage it effectively. This includes monitoring disk group space usage, rebalancing data across disks, adding or removing disks from disk groups, and various maintenance tasks.
It's important to consult the official Oracle documentation or seek assistance from an experienced Oracle DBA for detailed instructions and best practices specific to your environment.
What is ASM diskgroup compatibility?
ASM diskgroup compatibility refers to the version or level of compatibility between the Oracle ASM software and the ASM diskgroup. It determines the set of features and functionality that can be used within an ASM diskgroup.
The ASM diskgroup compatibility compatibility levels are designated by a three-digit format, such as "a.b.c", where "a" represents the major version number of the ASM software, "b" represents the minimum compatible version of the ASM software, and "c" represents the minimum compatible version of the database software.
The ASM diskgroup compatibility level determines the following:
- Features: It determines which features are available and supported within the diskgroup. Higher compatibility levels generally provide access to more advanced features.
- Online migration: It allows for the online movement of disks or disk groups between systems running different versions of ASM software.
- Rolling upgrade: It enables the ability to perform rolling upgrades of ASM software without interrupting database availability.
It is important to ensure that the ASM diskgroup compatibility level is set appropriately to ensure compatibility between the ASM software and the database software. The compatibility level can be set when creating a new diskgroup or can be modified for existing diskgroups.
What is ASM data redundancy?
ASM (Automatic Storage Management) data redundancy refers to the duplication of data across multiple disk drives or failure groups within a storage system managed by ASM. ASM is a feature provided by Oracle Database to manage storage for database files, and it includes features for automatic mirroring and redundancy.
ASM redundancy can be configured at various levels: disk group redundancy, file redundancy, and allocation unit redundancy.
- Disk Group Redundancy: ASM allows the creation of disk groups, which consist of several disks. It provides options to choose the level of redundancy, such as normal redundancy, high redundancy, or external redundancy. Normal and high redundancy provide mirroring of data by default, ensuring multiple copies of the same data across different disks in a disk group. If a disk fails, ASM automatically retrieves the data from the duplicate copy.
- File Redundancy: Within a disk group, an ASM file can be created with redundancy settings. The redundancy for a file can be set to high, normal, or none. High redundancy ensures that the file has multiple copies stored in different failure groups and disks.
- Allocation Unit Redundancy: ASM divides the data within a file into small units called allocation units (AU). These AUs are distributed across multiple disks for performance and redundancy. Multiple copies of an AU are maintained in different failure groups to ensure data durability in case of disk or failure group failures.
By providing these redundancy options, ASM ensures the availability and reliability of data in case of disk failures or other failures within the storage system.
How to set up ASM redundancy for data protection?
To set up ASM (Automatic Storage Management) redundancy for data protection, you can follow these steps:
- Choose a suitable redundancy level: ASM offers three redundancy levels - HIGH, NORMAL, and EXTERNAL. Decide which level meets your data protection requirements and performance goals.
- Configure disk groups: Disk groups are virtual storage containers that hold the ASM disks. Create a disk group using the CREATE DISKGROUP statement, specifying the redundancy level you selected earlier. For example, to create a disk group with HIGH redundancy level, you can use the following command: CREATE DISKGROUP dg_name REDUNDANCY HIGH DISK '/dev/sd*'; Replace 'dg_name' with your desired disk group name and '/dev/sd*' with the appropriate disk paths.
- Add disks to the disk group: Once the disk group is created, add the ASM disks to it using the ALTER DISKGROUP statement. For example: ALTER DISKGROUP dg_name ADD DISK '/dev/sdx1' NAME 'disk1', '/dev/sdy1' NAME 'disk2'; Replace 'dg_name' with the name of your disk group and provide the appropriate disk paths and names.
- Check the redundancy level: Verify the redundancy level of the newly created disk group and ensure it matches your chosen level. You can use the V$ASM_DISKGROUP view or the ASMCA (ASM Configuration Assistant) graphical tool for this purpose.
- Rebalance the data: If necessary, initiate a rebalance operation on the disk group to evenly distribute data across all the disks within the group. This helps maintain redundancy and performance.
By setting up ASM redundancy properly, you can ensure that data is protected against disk failures and maintain high availability of your database. It is important to regularly monitor the health and status of ASM disks, as well as perform regular backups for ultimate data protection.