GridStor® (Alternate Data Paths) - Overview
A data path is the combination of MediaAgent, Library, Drive Pool, and Scratch Pool that are used by the storage policy copy to perform a backup operation. Each storage policy copy has a default data path that is used to perform backup operations.
You can define alternate data paths in each of the storage policy copy to ensure the success of backup and other operations that use the storage policy. In addition, alternate data paths provide the following advantages:
- Automatic switch-over to an alternate data path when one of the components in the default data path is not available.
- Usage of available libraries and drives in the event of failure or non-availability of these resources.
- Instead of creating several storage policies that use different media for each subclient, you can minimize media usage by routing backup operations from several subclients to the same storage policy, and, therefore, the same media.
- Load-balancing (round-robin) between alternate data paths, which provides evenly-distributed backup operations among available resources.
- You can define the priority order of data paths at the subclient level within the selected storage policy and its data paths.
The diagram above illustrates the LAN-free MediaAgent that is configured with a default data path and an alternate data path.
Alternate data paths are supported for both the primary and secondary copies that are associated with storage policies for all libraries. (See GridStor (Alternate Data Paths) - Support for additional details.) However, there are several differences between the operations that are performed using primary and secondary copies with alternate data paths.
How GridStor® (Alternate Data Paths) Works
GridStor is made up of three options:
- Alternate data paths
- Preferred data paths
- Round-robin between data paths
By default, the system uses only LAN-free data paths. However, you can configure the system to use the appropriate data path that suits your needs.
|Alternate Data Paths||Preferred Data Paths||Round-Robin Between Data Paths|
|Client is a MediaAgent in the data path||Use LAN-free data path||Use LAN-free data path||Use LAN-free data path|
|Client is not a MediaAgent in the data path||Use default data path||Use default data path||Use round-robin between data paths|
|Client is a MediaAgent in the data path, but offline||Use alternate data path||Job waits||Use round-robin between data paths|
If an override data path is set at the subclient level, failover uses the data path according to the priority order that is assigned.