IntelliSnap - Overview - PostgreSQL iDataAgent
IntelliSnap backup enables you to create a point-in-time snapshot of the data used for backups. An effective way to back up live data is to quiesce it temporarily, take a snapshot, and then resume live operations. IntelliSnap backup works in conjunction with storage arrays to provide snapshot functionality for backup.
You can perform a full IntelliSnap backup of the PostgreSQL database using the PostgreSQL iDataAgent. IntelliSnap backup is only supported for a file system based backup set, FSBasedBackupSet. IntelliSnap backup cannot be performed on the logs. Log backup runs as a traditional backup. When you switch from a snap to a traditional backup or vice-versa, the next job is converted to a full backup. While performing an IntelliSnap backup or any subsequent operations, you can use a proxy server to reduce the load on the production server. Also, the backup copy operation will use the proxy to move the snap to backup media. Proxy server is supported with hardware storage arrays.
The following illustration describes the process involved in IntelliSnap backup:
Advantages of Using IntelliSnap Backup
The traditional dump backups run based on the queries on the database server. During this backup operation, depending on the storage engine used, the tables might be locked for the entire duration of the backup operation. If the database size is huge, the load and availability of the server for the clients might get affected.
You can overcome this issue by performing the IntelliSnap backup for PostgreSQL. In this case, the snap backups lock the tables only for few seconds during the snapshot creation, irrespective of the storage engine used. With the IntelliSnap technology, we can create backups of huge databases within few seconds.
The following table lists some of the advantages of using IntelliSnap backup over other available backup solutions.
|Feature Support||Generic Software Solution||Commvault IntelliSnap Backup|
|Backup to Tape|
|Hardware Agnostic - No dependency on the hardware array vendor changes|
|Snapshot copy, backup copy, and tape copy creation and management are seamless. Application aware snapshots creation can be scheduled. The snapshots can be cataloged/indexed for restore and Backup Copy based on policies.|
|To reduce load on the production server, a proxy server can be used for operations like Backup Copy, integrity check.|
|Restores can be performed directly from media to the application server.|
|Ability to mix and match IntelliSnap backup with traditional backups. You can perform full IntelliSnap backups combined with incremental log backups being moved to media and still perform a seamless restore.|
|All data management operations can be performed from the CommCell Console.|
Advantages of Using IntelliSnap Backup with PostgreSQL
IntelliSnap backups of PostgreSQL FSBasedBackupSet provide the following additional benefits:
- Ability to backup large databases (in tera and peta bytes) within few minutes.
- Ability to obtain consistent backups.
- Transaction log backups enable you to recover the database to any specific point-in-time.
- The files can be backed up to tape or magnetic library.
- Fast recovery using application aware revert operation.
- Ability to schedule backups.
- Ability to restore from media to a database server.
Backup job is scheduled using the CommCell Console. When the backup job is started:
- The array is accessed to create a snapshot.
- The snapshot is mounted on the proxy or source computer for post backup operations.
- The snapshot is unmounted.
This snapshot is used for backup copy operations. This can also be used for restore/mount operations.
During the Backup Copy operations:
- The snapshot is mounted to the source or proxy computer.
- The mounted snapshot is treated like a file system and the required contents are read.
- The file system backup is performed on the Primary Copy of the storage policy.
- When the backup copy job is finished, the snapshot is unmounted.
- The jobs for the snapshot are pruned based on the retention policy for the snapshot copy.
- The snapshots that are related to the pruned jobs are deleted from the array periodically.
The IntelliSnap Backup documentation uses the following terminology:
|Storage Device||A device used for backup or archival purposes.|
|Storage Array||A high-end disk storage system. The IntelliSnap software is designed to work in conjunction with the snapshot ability built into the storage array.|
|Proxy||A computer other than the production server on which you can perform IntelliSnap operations. A proxy is used to decrease the load on the production server.|
|Snapshot Copy||An additional copy of the protected data that is used in IntelliSnap operations.|